Method whereby sidelink terminal transmits pscch in wireless communications system, and device therefor

ABSTRACT

One embodiment relates to a sidelink terminal device which transmits a PSCCH in a wireless communications system, the device comprising: a memory; and a processor coupled to the memory, wherein the processor transmits a PSCCH by using at least some resources among PSCCH candidate resources associated with PSSCH candidate resources, and the resources for transmitting the PSCCH include a number Z of sequential resource blocks (RBs) and also include the center frequency of the PSCCH candidate resources on the frequency axis.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a National Stage application under 35 U.S.C. § 371of International Application No. PCT/KR2019/012265, filed on Sep. 20,2019, which claims the benefit of U.S. Provisional Application No.62/734,198, filed on Sep. 20, 2018, 62/734,203, filed on Sep. 20, 2018,and 62/734,205, filed on Sep. 20, 2018. The disclosures of the priorapplications are incorporated by reference in their entirety.

TECHNICAL FIELD

The following description relates to a wireless communication systemand, more particularly, to a method and apparatus for effectivelydetermining transmission resources of a physical sidelink controlchannel (PSCCH) corresponding to a control channel in new radio accesstechnology (NR) vehicle-to-everything (V2X) and transmitting the PSCCH.

BACKGROUND

Wireless communication systems have been widely deployed to providevarious types of communication services such as voice or data. Ingeneral, a wireless communication system is a multiple access systemthat supports communication of multiple users by sharing availablesystem resources (a bandwidth, transmission power, etc.). Examples ofmultiple access systems include a code division multiple access (CDMA)system, a frequency division multiple access (FDMA) system, a timedivision multiple access (TDMA) system, an orthogonal frequency divisionmultiple access (OFDMA) system, a single carrier frequency divisionmultiple access (SC-FDMA) system, and a multi carrier frequency divisionmultiple access (MC-FDMA) system.

A wireless communication system uses various radio access technologies(RATs) such as long term evolution (LTE), LTE-advanced (LTE-A), andwireless fidelity (WiFi). 5th generation (5G) is such a wirelesscommunication system. Three key requirement areas of 5G include (1)enhanced mobile broadband (eMBB), (2) massive machine type communication(mMTC), and (3) ultra-reliable and low latency communications (URLLC).Some use cases may require multiple dimensions for optimization, whileothers may focus only on one key performance indicator (KPI). 5Gsupports such diverse use cases in a flexible and reliable way.

eMBB goes far beyond basic mobile Internet access and covers richinteractive work, media and entertainment applications in the cloud oraugmented reality (AR). Data is one of the key drivers for 5G and in the5G era, we may for the first time see no dedicated voice service. In 5G,voice is expected to be handled as an application program, simply usingdata connectivity provided by a communication system. The main driversfor an increased traffic volume are the increase in the size of contentand the number of applications requiring high data rates. Streamingservices (audio and video), interactive video, and mobile Internetconnectivity will continue to be used more broadly as more devicesconnect to the Internet. Many of these applications require always-onconnectivity to push real time information and notifications to users.Cloud storage and applications are rapidly increasing for mobilecommunication platforms. This is applicable for both work andentertainment. Cloud storage is one particular use case driving thegrowth of uplink data rates. 5G will also be used for remote work in thecloud which, when done with tactile interfaces, requires much lowerend-to-end latencies in order to maintain a good user experience.Entertainment, for example, cloud gaming and video streaming, is anotherkey driver for the increasing need for mobile broadband capacity.Entertainment will be very essential on smart phones and tabletseverywhere, including high mobility environments such as trains, carsand airplanes. Another use case is augmented reality (AR) forentertainment and information search, which requires very low latenciesand significant instant data volumes.

One of the most expected 5G use cases is the functionality of activelyconnecting embedded sensors in every field, that is, mMTC. It isexpected that there will be 20.4 billion potential Internet of things(IoT) devices by 2020. In industrial IoT, 5G is one of areas that playkey roles in enabling smart city, asset tracking, smart utility,agriculture, and security infrastructure.

URLLC includes services which will transform industries withultra-reliable/available, low latency links such as remote control ofcritical infrastructure and self-driving vehicles. The level ofreliability and latency are vital to smart-grid control, industrialautomation, robotics, drone control and coordination, and so on.

Now, multiple use cases will be described in detail.

5G may complement fiber-to-the home (FTTH) and cable-based broadband (ordata-over-cable service interface specifications (DOCSIS)) as a means ofproviding streams at data rates of hundreds of megabits per second togiga bits per second. Such a high speed is required for TV broadcasts ator above a resolution of 4K (6K, 8K, and higher) as well as virtualreality (VR) and AR. VR and AR applications mostly include immersivesport games. A special network configuration may be required for aspecific application program. For VR games, for example, game companiesmay have to integrate a core server with an edge network server of anetwork operator in order to minimize latency.

The automotive sector is expected to be a very important new driver for5G, with many use cases for mobile communications for vehicles. Forexample, entertainment for passengers requires simultaneous highcapacity and high mobility mobile broadband, because future users willexpect to continue their good quality connection independent of theirlocation and speed. Other use cases for the automotive sector are ARdashboards. These display overlay information on top of what a driver isseeing through the front window, identifying objects in the dark andtelling the driver about the distances and movements of the objects. Inthe future, wireless modules will enable communication between vehiclesthemselves, information exchange between vehicles and supportinginfrastructure and between vehicles and other connected devices (e.g.,those carried by pedestrians). Safety systems may guide drivers onalternative courses of action to allow them to drive more safely andlower the risks of accidents. The next stage will be remote-controlledor self-driving vehicles. These require very reliable, very fastcommunication between different self-driving vehicles and betweenvehicles and infrastructure. In the future, self-driving vehicles willexecute all driving activities, while drivers are focusing on trafficabnormality elusive to the vehicles themselves. The technicalrequirements for self-driving vehicles call for ultra-low latencies andultra-high reliability, increasing traffic safety to levels humanscannot achieve.

Smart cities and smart homes, often referred to as smart society, willbe embedded with dense wireless sensor networks. Distributed networks ofintelligent sensors will identify conditions for cost- andenergy-efficient maintenance of the city or home. A similar setup can bedone for each home, where temperature sensors, window and heatingcontrollers, burglar alarms, and home appliances are all connectedwirelessly. Many of these sensors are typically characterized by lowdata rate, low power, and low cost, but for example, real time highdefinition (HD) video may be required in some types of devices forsurveillance.

The consumption and distribution of energy, including heat or gas, isbecoming highly decentralized, creating the need for automated controlof a very distributed sensor network. A smart grid interconnects suchsensors, using digital information and communications technology togather and act on information. This information may include informationabout the behaviors of suppliers and consumers, allowing the smart gridto improve the efficiency, reliability, economics and sustainability ofthe production and distribution of fuels such as electricity in anautomated fashion. A smart grid may be seen as another sensor networkwith low delays.

The health sector has many applications that may benefit from mobilecommunications. Communications systems enable telemedicine, whichprovides clinical health care at a distance. It helps eliminate distancebarriers and may improve access to medical services that would often notbe consistently available in distant rural communities. It is also usedto save lives in critical care and emergency situations. Wireless sensornetworks based on mobile communication may provide remote monitoring andsensors for parameters such as heart rate and blood pressure.

Wireless and mobile communications are becoming increasingly importantfor industrial applications. Wires are expensive to install andmaintain, and the possibility of replacing cables with reconfigurablewireless links is a tempting opportunity for many industries. However,achieving this requires that the wireless connection works with asimilar delay, reliability and capacity as cables and that itsmanagement is simplified. Low delays and very low error probabilitiesare new requirements that need to be addressed with 5G.

Finally, logistics and freight tracking are important use cases formobile communications that enable the tracking of inventory and packageswherever they are by using location-based information systems. Thelogistics and freight tracking use cases typically require lower datarates but need wide coverage and reliable location information.

SUMMARY

Embodiment(s) relate to a method of effectively determining transmissionresources of a PSCCH corresponding to a control channel in NR V2X andtransmitting the PSCCH.

Technical objects to be achieved by embodiment(s) are not limited towhat has been particularly described hereinabove and other technicalobjects not mentioned herein will be more clearly understood by personsskilled in the art to which embodiment(s) pertain from the followingdetailed description.

According to an embodiment, provided herein is a method of transmittinga physical sidelink control channel (PSCCH) by a sidelink user equipment(UE) in a wireless communication system, including determining PSCCHcandidate resources associated with physical sidelink shared channel(PSSCH) candidate resources; and transmitting a PSCCH using at leastsome resources among the PSCCH candidate resources, wherein the at leastsome resources include Z successive resource blocks (RBs) and include acenter frequency of the PSCCH candidate resources on a frequency axis.

According to an embodiment, provided herein is a sidelink user equipment(UE) for transmitting a physical sidelink control channel (PSCCH) in awireless communication system, including a memory; and a processorcoupled to the memory, wherein the processor is configured to transmit aPSCCH using at least some resources among PSCCH candidate resourcesassociated with physical sidelink shared channel (PSSCH) candidateresources, and wherein the resources used to transmit the PSCCH includeZ successive resource blocks (RBs) and include a center frequency of thePSCCH candidate resources on a frequency axis.

Z may be uniform regardless of change in a size of the associated PSSCHcandidate resources.

A resource region irrelevant to the resources used to transmit the PSCCHmay be related to a guard band of the PSCCH.

The PSCCH candidate resources associated with the PSSCH candidateresources may have a size of a frequency resource region equal to a sizeof a frequency resource region of the PSSCH candidate resources.

Based on the PSCCH candidate resources associated with the PSSCHcandidate resources, the PSCCH transmitted on some of the PSCCHcandidate resources may include control information for a PSSCHtransmitted on the PSSCH candidate resources or feedback information ofthe PSSCH.

Z may be related to X % of the number of RBs related to the PSCCHcandidate resources.

X may be determined by at least one of a channel busy ratio (CBR),priority, latency, or reliability.

X may haves a small value as the UE or a packet has a high priority.

X may be set with respect to each format of the PSCCH.

The PSCCH candidate resources may not include a sub-channel located atan edge of a total frequency bandwidth.

Based on the PSCCH candidate resources including a sub-channel locatedat an edge of a total frequency bandwidth, the PSCCH transmissionresources may be included in a sub-channel located at the edge.

The at least some resources may be selected from a resource regionexcluding a sub-channel of Y % of the PSCCH candidate resources.

Y may be determined by at least one of a channel busy ratio (CBR),priority, latency, or reliability.

The UE may be an autonomous driving vehicle or may be included in theautonomous driving vehicle.

According to an embodiment, PSCCH transmission may be performed whilemaximally suppressing an influence of interference such as in-bandemission (IBE).

Effects to be achieved by embodiment(s) are not limited to what has beenparticularly described hereinabove and other effects not mentionedherein will be more clearly understood by persons skilled in the art towhich embodiment(s) pertain from the following detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of embodiment(s), illustrate various implementations andtogether with the detailed description serve to explain the principle ofthe disclosure.

FIG. 1 is a diagram showing a vehicle according to embodiment(s).

FIG. 2 is a control block diagram of the vehicle according toembodiment(s).

FIG. 3 is a control block diagram of an autonomous driving deviceaccording to embodiment(s).

FIG. 4 is a block diagram of the autonomous driving device according toembodiment(s).

FIG. 5 is a diagram showing the interior of a vehicle according toembodiment(s).

FIG. 6 is a block diagram for explaining a vehicle cabin systemaccording to embodiment(s).

FIG. 7 illustrates the structure of an LTE system to which embodiment(s)are applicable.

FIG. 8 illustrates a user-plane radio protocol architecture to whichembodiment(s) are applicable.

FIG. 9 illustrates a control-plane radio protocol architecture to whichembodiment(s) are applicable.

FIG. 10 illustrates the structure of an NR system to which embodiment(s)are applicable.

FIG. 11 illustrates functional split between an NG-RAN and a 5GC towhich embodiment(s) are applicable.

FIG. 12 illustrates the structure of an NR radio frame to whichembodiment(s) are applicable.

FIG. 13 illustrates the slot structure of an NR frame to whichembodiment(s) are applicable.

FIG. 14 illustrates transmission resource selection in which atransmission resource for a next packet is also reserved.

FIG. 15 illustrates an example of PSCCH transmission in sidelinktransmission mode 3 or 4 to which embodiments(s) are applicable.

FIG. 16 illustrates an example of physical layer processing at atransmitting side to which embodiments(s) are applicable.

FIG. 17 illustrates an example of physical layer processing at areceiving side to which embodiments(s) are applicable.

FIG. 18 illustrates a V2X synchronization source or synchronizationreference to which embodiments(s) are applicable.

FIG. 19 illustrates an SS/PBCH block to which embodiments(s) areapplicable.

FIG. 20 is a diagram for explaining a method of acquiring timinginformation to which embodiments(s) are applicable.

FIG. 21 is a diagram for explaining a process of acquiring systeminformation to which embodiments(s) are applicable.

FIG. 22 is a diagram for explaining a random access procedure to whichembodiments(s) are applicable.

FIG. 23 is a diagram for explaining a threshold of an SS block to whichembodiments(s) are applicable.

FIG. 24 is a diagram for explaining beam switching for PRACHretransmission to which embodiments(s) are applicable.

FIGS. 25 and 26 illustrate parity check matrixes to which embodiments(s)are applicable.

FIG. 27 illustrates an encoder structure for polar code to whichembodiments(s) are applicable.

FIG. 28 illustrates channel combining and channel splitting to whichembodiments(s) are applicable.

FIG. 29 illustrates an UE RRC state transition to which embodiments(s)are applicable.

FIG. 30 illustrates state transition between an NR/NGC and anE-UTRAN/EPC to which embodiments(s) are applicable.

FIG. 31 is a diagram for explaining DRX to which embodiments(s) areapplicable.

FIG. 32 is a diagram for explaining IBE.

FIG. 33 is a flowchart for explaining embodiment(s).

FIGS. 34 to 38 are diagrams for explaining embodiment(s).

FIGS. 39 to 45 are diagrams for explaining various devices to whichembodiment(s) are applicable.

DETAILED DESCRIPTION

1. Driving

(1) Exterior of Vehicle

FIG. 1 is a diagram showing a vehicle according to an implementation ofthe present disclosure.

Referring to FIG. 1 , a vehicle 10 according to an implementation of thepresent disclosure is defined as transportation traveling on roads orrailroads. The vehicle 10 includes a car, a train, and a motorcycle. Thevehicle 10 may include an internal-combustion engine vehicle having anengine as a power source, a hybrid vehicle having an engine and a motoras a power source, and an electric vehicle having an electric motor as apower source. The vehicle 10 may be a private own vehicle or a sharedvehicle. The vehicle 10 may be an autonomous vehicle.

(2) Components of Vehicle

FIG. 2 is a control block diagram of the vehicle according to animplementation of the present disclosure.

Referring to FIG. 2 , the vehicle 10 may include a user interface device200, an object detection device 210, a communication device 220, adriving operation device 230, a main electronic control unit (ECU) 240,a driving control device 250, an autonomous driving device 260, asensing unit 270, and a location data generating device 280. Each of theobject detection device 210, communication device 220, driving operationdevice 230, main ECU 240, driving control device 250, autonomous drivingdevice 260, sensing unit 270, and location data generating device 280may be implemented as an electronic device that generates an electricalsignal and exchanges the electrical signal from one another.

1) User Interface Device

The user interface device 200 is a device for communication between thevehicle 10 and a user. The user interface device 200 may receive a userinput and provide information generated in the vehicle 10 to the user.The vehicle 10 may implement a user interface (UI) or user experience(UX) through the user interface device 200. The user interface device200 may include an input device, an output device, and a user monitoringdevice.

2) Object Detection Device

The object detection device 210 may generate information about an objectoutside the vehicle 10. The object information may include at least oneof information about the presence of the object, information about thelocation of the object, information about the distance between thevehicle 10 and the object, and information about the relative speed ofthe vehicle 10 with respect to the object. The object detection device210 may detect the object outside the vehicle 10. The object detectiondevice 210 may include at least one sensor to detect the object outsidethe vehicle 10. The object detection device 210 may include at least oneof a camera, a radar, a lidar, an ultrasonic sensor, and an infraredsensor. The object detection device 210 may provide data about theobject, which is created based on a sensing signal generated by thesensor, to at least one electronic device included in the vehicle 10.

2.1) Camera

The camera may generate information about an object outside the vehicle10 with an image. The camera may include at least one lens, at least oneimage sensor, and at least one processor electrically connected to theimage sensor and configured to process a received signal and generatedata about the object based on the processed signal.

The camera may be at least one of a mono camera, a stereo camera, and anaround view monitoring (AVM) camera. The camera may acquire informationabout the location of the object, information about the distance to theobject, or information about the relative speed thereof with respect tothe object based on various image processing algorithms. For example,the camera may acquire the information about the distance to the objectand the information about the relative speed with respect to the objectfrom the image based on a change in the size of the object over time.For example, the camera may acquire the information about the distanceto the object and the information about the relative speed with respectto the object through a pin-hole model, road profiling, etc. Forexample, the camera may acquire the information about the distance tothe object and the information about the relative speed with respect tothe object from a stereo image generated by a stereo camera based ondisparity information.

The camera may be disposed at a part of the vehicle 10 where the fieldof view (FOV) is guaranteed to photograph the outside of the vehicle 10.The camera may be disposed close to a front windshield inside thevehicle 10 to acquire front-view images of the vehicle 10. The cameramay be disposed in the vicinity of a front bumper or a radiator grill.The camera may be disposed close to a rear glass inside the vehicle 10to acquire rear-view images of the vehicle 10. The camera may bedisposed in the vicinity of a rear bumper, a trunk, or a tail gate. Thecamera may be disposed close to at least one of side windows inside thevehicle 10 in order to acquire side-view images of the vehicle 10.Alternatively, the camera may be disposed in the vicinity of a sidemirror, a fender, or a door.

2.2) Radar

The radar may generate information about an object outside the vehicle10 using electromagnetic waves. The radar may include an electromagneticwave transmitter, an electromagnetic wave receiver, and at least oneprocessor electrically connected to the electromagnetic wave transmitterand the electromagnetic wave receiver and configured to process areceived signal and generate data about the object based on theprocessed signal. The radar may be a pulse radar or a continuous waveradar depending on electromagnetic wave emission. The continuous waveradar may be a frequency modulated continuous wave (FMCW) radar or afrequency shift keying (FSK) radar depending on signal waveforms. Theradar may detect the object from the electromagnetic waves based on thetime of flight (TOF) or phase shift principle and obtain the location ofthe detected object, the distance to the detected object, and therelative speed with respect to the detected object. The radar may bedisposed at an appropriate position outside the vehicle 10 to detectobjects placed in front, rear, or side of the vehicle 10.

2.3) Lidar

The lidar may generate information about an object outside the vehicle10 using a laser beam. The lidar may include a light transmitter, alight receiver, and at least one processor electrically connected to thelight transmitter and the light receiver and configured to process areceived signal and generate data about the object based on theprocessed signal. The lidar may operate based on the TOF or phase shiftprinciple. The lidar may be a driven type or a non-driven type. Thedriven type of lidar may be rotated by a motor and detect an objectaround the vehicle 10. The non-driven type of lidar may detect an objectwithin a predetermined range from the vehicle 10 based on lightsteering. The vehicle 10 may include a plurality of non-driven type oflidars. The lidar may detect the object from the laser beam based on theTOF or phase shift principle and obtain the location of the detectedobject, the distance to the detected object, and the relative speed withrespect to the detected object. The lidar may be disposed at anappropriate position outside the vehicle 10 to detect objects placed infront, rear, or side of the vehicle 10.

3) Communication Device

The communication device 220 may exchange a signal with a device outsidethe vehicle 10. The communication device 220 may exchange a signal withat least one of an infrastructure (e.g., server, broadcast station,etc.), another vehicle, and a terminal. The communication device 220 mayinclude a transmission antenna, a reception antenna, and at least one ofa radio frequency (RF) circuit and an RF element where variouscommunication protocols may be implemented to perform communication.

For example, the communication device 220 may exchange a signal with anexternal device based on the cellular vehicle-to-everything (C-V2X)technology. The C-V2X technology may include LTE-based sidelinkcommunication and/or NR-based sidelink communication. Details related tothe C-V2X technology will be described later.

The communication device 220 may exchange the signal with the externaldevice according to dedicated short-range communications (DSRC)technology or wireless access in vehicular environment (WAVE) standardsbased on IEEE 802.11p PHY/MAC layer technology and IEEE 1609Network/Transport layer technology. The DSRC technology (or WAVEstandards) is communication specifications for providing intelligenttransport system (ITS) services through dedicated short-rangecommunication between vehicle-mounted devices or between a road sideunit and a vehicle-mounted device. The DSRC technology may be acommunication scheme that allows the use of a frequency of 5.9 GHz andhas a data transfer rate in the range of 3 Mbps to 27 Mbps. IEEE 802.11pmay be combined with IEEE 1609 to support the DSRC technology (or WAVEstandards).

According to the present disclosure, the communication device 220 mayexchange the signal with the external device according to either theC-V2X technology or the DSRC technology. Alternatively, thecommunication device 220 may exchange the signal with the externaldevice by combining the C-V2X technology and the DSRC technology.

4) Driving Operation Device

The driving operation device 230 is configured to receive a user inputfor driving. In a manual mode, the vehicle 10 may be driven based on asignal provided by the driving operation device 230. The drivingoperation device 230 may include a steering input device (e.g., steeringwheel), an acceleration input device (e.g., acceleration pedal), and abrake input device (e.g., brake pedal).

5) Main ECU

The main ECU 240 may control the overall operation of at least oneelectronic device included in the vehicle 10.

6) Driving Control Device

The driving control device 250 is configured to electrically controlvarious vehicle driving devices included in the vehicle 10. The drivingcontrol device 250 may include a power train driving control device, achassis driving control device, a door/window driving control device, asafety driving control device, a lamp driving control device, and anair-conditioner driving control device. The power train driving controldevice may include a power source driving control device and atransmission driving control device. The chassis driving control devicemay include a steering driving control device, a brake driving controldevice, and a suspension driving control device. The safety drivingcontrol device may include a seat belt driving control device for seatbelt control.

The driving control device 250 includes at least one electronic controldevice (e.g., control ECU).

The driving control device 250 may control the vehicle driving devicebased on a signal received from the autonomous driving device 260. Forexample, the driving control device 250 may control a power train, asteering, and a brake based on signals received from the autonomousdriving device 260.

7) Autonomous Driving Device

The autonomous driving device 260 may generate a route for autonomousdriving based on obtained data. The autonomous driving device 260 maygenerate a driving plan for traveling along the generated route. Theautonomous driving device 260 may generate a signal for controlling themovement of the vehicle 10 according to the driving plan. The autonomousdriving device 260 may provide the generated signal to the drivingcontrol device 250.

The autonomous driving device 260 may implement at least one advanceddriver assistance system (ADAS) function. The ADAS may implement atleast one of adaptive cruise control (ACC), autonomous emergency braking(AEB), forward collision warning (FCW), lane keeping assist (LKA), lanechange assist (LCA), target following assist (TFA), blind spot detection(BSD), high beam assist (HBA), auto parking system (APS), PD collisionwarning system, traffic sign recognition (TSR), traffic sign assist(TSA), night vision (NV), driver status monitoring (DSM), and trafficjam assist (TJA).

The autonomous driving device 260 may perform switching from anautonomous driving mode to a manual driving mode or switching from themanual driving mode to the autonomous driving mode. For example, theautonomous driving device 260 may switch the mode of the vehicle 10 fromthe autonomous driving mode to the manual driving mode or from themanual driving mode to the autonomous driving mode based on a signalreceived from the user interface device 200.

8) Sensing Unit

The sensing unit 270 may detect the state of the vehicle 10. The sensingunit 270 may include at least one of an inertial measurement unit (IMU)sensor, a collision sensor, a wheel sensor, a speed sensor, aninclination sensor, a weight sensor, a heading sensor, a positionmodule, a vehicle forward/backward movement sensor, a battery sensor, afuel sensor, a tire sensor, a steering sensor, a temperature sensor, ahumidity sensor, an ultrasonic sensor, an illumination sensor, and apedal position sensor. Further, the IMU sensor may include at least oneof an acceleration sensor, a gyro sensor, and a magnetic sensor.

The sensing unit 270 may generate data about the vehicle state based ona signal generated by at least one sensor. The vehicle state data may beinformation generated based on data detected by various sensors includedin the vehicle 10. The sensing unit 270 may generate vehicle attitudedata, vehicle motion data, vehicle yaw data, vehicle roll data, vehiclepitch data, vehicle collision data, vehicle orientation data, vehicleangle data, vehicle speed data, vehicle acceleration data, vehicle tiltdata, vehicle forward/backward movement data, vehicle weight data,battery data, fuel data, tire pressure data, vehicle internaltemperature data, vehicle internal humidity data, steering wheelrotation angle data, vehicle external illumination data, data onpressure applied to the acceleration pedal, data on pressure applied tothe brake pedal, etc.

9) Location Data Generating Device

The location data generating device 280 may generate data on thelocation of the vehicle 10. The location data generating device 280 mayinclude at least one of a global positioning system (GPS) and adifferential global positioning system (DGPS). The location datagenerating device 280 may generate the location data on the vehicle 10based on a signal generated by at least one of the GPS and the DGPS. Insome implementations, the location data generating device 280 maycorrect the location data based on at least one of the IMU sensor of thesensing unit 270 and the camera of the object detection device 210. Thelocation data generating device 280 may also be called a globalnavigation satellite system (GNSS).

The vehicle 10 may include an internal communication system 50. Theplurality of electronic devices included in the vehicle 10 may exchangea signal through the internal communication system 50. The signal mayinclude data. The internal communication system 50 may use at least onecommunication protocol (e.g., CAN, LIN, FlexRay, MOST, or Ethernet).

(3) Components of Autonomous Driving Device

FIG. 3 is a control block diagram of the autonomous driving device 260according to an implementation of the present disclosure.

Referring to FIG. 3 , the autonomous driving device 260 may include amemory 140, a processor 170, an interface 180 and a power supply 190.

The memory 140 is electrically connected to the processor 170. Thememory 140 may store basic data about a unit, control data forcontrolling the operation of the unit, and input/output data. The memory140 may store data processed by the processor 170. In hardwareimplementation, the memory 140 may be implemented as any one of a ROM, aRAM, an EPROM, a flash drive, and a hard drive. The memory 140 may storevarious data for the overall operation of the autonomous driving device260, such as a program for processing or controlling the processor 170.The memory 140 may be integrated with the processor 170. In someimplementations, the memory 140 may be classified as a subcomponent ofthe processor 170.

The interface 180 may exchange a signal with at least one electronicdevice included in the vehicle 10 by wire or wirelessly. The interface180 may exchange a signal with at least one of the object detectiondevice 210, the communication device 220, the driving operation device230, the main ECU 240, the driving control device 250, the sensing unit270, and the location data generating device 280 by wire or wirelessly.The interface 180 may be implemented with at least one of acommunication module, a terminal, a pin, a cable, a port, a circuit, anelement, and a device.

The power supply 190 may provide power to the autonomous driving device260. The power supply 190 may be provided with power from a power source(e.g., battery) included in the vehicle 10 and supply the power to eachunit of the autonomous driving device 260. The power supply 190 mayoperate according to a control signal from the main ECU 240. The powersupply 190 may include a switched-mode power supply (SMPS).

The processor 170 may be electrically connected to the memory 140, theinterface 180, and the power supply 190 to exchange signals with thecomponents. The processor 170 may be implemented with at least one ofapplication specific integrated circuits (ASICs), digital signalprocessors (DSPs), digital signal processing devices (DSPDs),programmable logic devices (PLDs), field programmable gate arrays(FPGAs), processors, controllers, micro-controllers, microprocessors,and electronic units for executing other functions.

The processor 170 may be driven by power supplied from the power supply190. The processor 170 may receive data, process the data, generate asignal, and provide the signal while the power is supplied thereto.

The processor 170 may receive information from other electronic devicesincluded in the vehicle 10 through the interface 180. The processor 170may provide a control signal to other electronic devices in the vehicle10 through the interface 180.

The autonomous driving device 260 may include at least one printedcircuit board (PCB). The memory 140, the interface 180, the power supply190, and the processor 170 may be electrically connected to the PCB.

(4) Operation of Autonomous Driving Device

1) Receiving Operation

Referring to FIG. 4 , the processor 170 may perform a receivingoperation. The processor 170 may receive data from at least one of theobject detection device 210, the communication device 220, the sensingunit 270, and the location data generating device 280 through theinterface 180. The processor 170 may receive object data from the objectdetection device 210. The processor 170 may receive HD map data from thecommunication device 220. The processor 170 may receive vehicle statedata from the sensing unit 270. The processor 170 may receive locationdata from the location data generating device 280.

2) Processing/Determination Operation

The processor 170 may perform a processing/determination operation. Theprocessor 170 may perform the processing/determination operation basedon driving state information. The processor 170 may perform theprocessing/determination operation based on at least one of object data,HD map data, vehicle state data, and location data.

2.1) Driving Plan Data Generating Operation

The processor 170 may generate driving plan data. For example, theprocessor 170 may generate electronic horizon data. The electronichorizon data may be understood as driving plan data from the currentlocation of the vehicle 10 to the horizon. The horizon may be understoodas a point away from the current location of the vehicle 10 by apredetermined distance along a predetermined traveling route. Further,the horizon may refer to a point at which the vehicle 10 may arriveafter a predetermined time from the current location of the vehicle 10along the predetermined traveling route.

The electronic horizon data may include horizon map data and horizonpath data.

2.1.1) Horizon Map Data

The horizon map data may include at least one of topology data, roaddata, HD map data and dynamic data. In some implementations, the horizonmap data may include a plurality of layers. For example, the horizon mapdata may include a first layer matching with the topology data, a secondlayer matching with the road data, a third layer matching with the HDmap data, and a fourth layer matching with the dynamic data. The horizonmap data may further include static object data.

The topology data may be understood as a map created by connecting roadcenters with each other. The topology data is suitable for representingan approximate location of a vehicle and may have a data form used fornavigation for drivers. The topology data may be interpreted as dataabout roads without vehicles. The topology data may be generated on thebasis of data received from an external server through the communicationdevice 220. The topology data may be based on data stored in at leastone memory included in the vehicle 10.

The road data may include at least one of road slope data, roadcurvature data, and road speed limit data. The road data may furtherinclude no-passing zone data. The road data may be based on datareceived from an external server through the communication device 220.The road data may be based on data generated by the object detectiondevice 210.

The HD map data may include detailed topology information including roadlanes, connection information about each lane, and feature informationfor vehicle localization (e.g., traffic sign, lane marking/property,road furniture, etc.). The HD map data may be based on data receivedfrom an external server through the communication device 220.

The dynamic data may include various types of dynamic information onroads. For example, the dynamic data may include constructioninformation, variable speed road information, road conditioninformation, traffic information, moving object information, etc. Thedynamic data may be based on data received from an external serverthrough the communication device 220. The dynamic data may be based ondata generated by the object detection device 210.

The processor 170 may provide map data from the current location of thevehicle 10 to the horizon.

2.1.2) Horizon Path Data

The horizon path data may be understood as a potential trajectory of thevehicle 10 when the vehicle 10 travels from the current location of thevehicle 10 to the horizon. The horizon path data may include dataindicating the relative probability of selecting a road at the decisionpoint (e.g., fork, junction, crossroad, etc.). The relative probabilitymay be calculated on the basis of the time taken to arrive at the finaldestination. For example, if the time taken to arrive at the finaldestination when a first road is selected at the decision point isshorter than that when a second road is selected, the probability ofselecting the first road may be calculated to be higher than theprobability of selecting the second road.

The horizon path data may include a main path and a sub-path. The mainpath may be understood as a trajectory obtained by connecting roads thatare highly likely to be selected. The sub-path may be branched from atleast one decision point on the main path. The sub-path may beunderstood as a trajectory obtained by connecting one or more roads thatare less likely to be selected at the at least one decision point on themain path.

3) Control Signal Generating Operation

The processor 170 may perform a control signal generating operation. Theprocessor 170 may generate a control signal on the basis of theelectronic horizon data. For example, the processor 170 may generate atleast one of a power train control signal, a brake device controlsignal, and a steering device control signal on the basis of theelectronic horizon data.

The processor 170 may transmit the generated control signal to thedriving control device 250 through the interface 180. The drivingcontrol device 250 may forward the control signal to at least one of apower train 251, a brake device 252 and a steering device 253.

2. Cabin

FIG. 5 is a diagram showing the interior of the vehicle 10 according toan implementation of the present disclosure.

FIG. 6 is a block diagram for explaining a vehicle cabin systemaccording to an implementation of the present disclosure.

Referring to FIGS. 5 and 6 , a vehicle cabin system 300 (cabin system)may be defined as a convenience system for the user who uses the vehicle10. The cabin system 300 may be understood as a high-end systemincluding a display system 350, a cargo system 355, a seat system 360,and a payment system 365. The cabin system 300 may include a maincontroller 370, a memory 340, an interface 380, a power supply 390, aninput device 310, an imaging device 320, a communication device 330, thedisplay system 350, the cargo system 355, the seat system 360, and thepayment system 365. In some implementations, the cabin system 300 mayfurther include components in addition to the components described inthis specification or may not include some of the components describedin this specification.

1) Main Controller

The main controller 370 may be electrically connected to the inputdevice 310, the communication device 330, the display system 350, thecargo system 355, the seat system 360, and the payment system 365 andexchange signals with the components. The main controller 370 maycontrol the input device 310, the communication device 330, the displaysystem 350, the cargo system 355, the seat system 360, and the paymentsystem 365. The main controller 370 may be implemented with at least oneof application specific integrated circuits (ASICs), digital signalprocessors (DSPs), digital signal processing devices (DSPDs),programmable logic devices (PLDs), field programmable gate arrays(FPGAs), processors, controllers, micro-controllers, microprocessors,and electronic units for executing other functions.

The main controller 370 may include at least one sub-controller. In someimplementations, the main controller 370 may include a plurality ofsub-controllers. The plurality of sub-controllers may control thedevices and systems included in the cabin system 300, respectively. Thedevices and systems included in the cabin system 300 may be grouped byfunctions or grouped with respect to seats for users.

The main controller 370 may include at least one processor 371. AlthoughFIG. 6 illustrates the main controller 370 including a single processor371, the main controller 371 may include a plurality of processors 371.The processor 371 may be classified as one of the above-describedsub-controllers.

The processor 371 may receive signals, information, or data from a userterminal through the communication device 330. The user terminal maytransmit signals, information, or data to the cabin system 300.

The processor 371 may identify the user on the basis of image datareceived from at least one of an internal camera and an external cameraincluded in the imaging device 320. The processor 371 may identify theuser by applying an image processing algorithm to the image data. Forexample, the processor 371 may identify the user by comparinginformation received from the user terminal with the image data. Forexample, the information may include information about at least one ofthe route, body, fellow passenger, baggage, location, preferred content,preferred food, disability, and use history of the user.

The main controller 370 may include an artificial intelligence agent372. The artificial intelligence agent 372 may perform machine learningon the basis of data acquired from the input device 310. The artificialintelligence agent 372 may control at least one of the display system350, the cargo system 355, the seat system 360, and the payment system365 on the basis of machine learning results.

2) Essential Components

The memory 340 is electrically connected to the main controller 370. Thememory 340 may store basic data about a unit, control data forcontrolling the operation of the unit, and input/output data. The memory340 may store data processed by the main controller 370. In hardwareimplementation, the memory 140 may be implemented as any one of a ROM, aRAM, an EPROM, a flash drive, and a hard drive. The memory 340 may storevarious types of data for the overall operation of the cabin system 300,such as a program for processing or controlling the main controller 370.The memory 340 may be integrated with the main controller 370.

The interface 380 may exchange a signal with at least one electronicdevice included in the vehicle 10 by wire or wirelessly. The interface380 may be implemented with at least one of a communication module, aterminal, a pin, a cable, a port, a circuit, an element and a device.

The power supply 390 may provide power to the cabin system 300. Thepower supply 390 may be provided with power from a power source (e.g.,battery) included in the vehicle 10 and supply the power to each unit ofthe cabin system 300. The power supply 390 may operate according to acontrol signal from the main controller 370. For example, the powersupply 390 may be implemented as a SMPS.

The cabin system 300 may include at least one PCB. The main controller370, the memory 340, the interface 380, and the power supply 390 may bemounted on at least one PCB.

3) Input Device

The input device 310 may receive a user input. The input device 310 mayconvert the user input into an electrical signal. The electrical signalconverted by the input device 310 may be converted into a control signaland provided to at least one of the display system 350, the cargo system355, the seat system 360, and the payment system 365. The maincontroller 370 or at least one processor included in the cabin system300 may generate a control signal based on an electrical signal receivedfrom the input device 310.

The input device 310 may include at least one of a touch input unit, agesture input unit, a mechanical input unit, and a voice input unit. Thetouch input unit may convert a touch input from the user into anelectrical signal. The touch input unit may include at least one touchsensor to detect the user's touch input. In some implementations, thetouch input unit may be implemented as a touch screen by integrating thetouch input unit with at least one display included in the displaysystem 350. Such a touch screen may provide both an input interface andan output interface between the cabin system 300 and the user. Thegesture input unit may convert a gesture input from the user into anelectrical signal. The gesture input unit may include at least one of aninfrared sensor and an image sensor to detect the user's gesture input.In some implementations, the gesture input unit may detect athree-dimensional gesture input from the user. To this end, the gestureinput unit may include a plurality of light output units for outputtinginfrared light or a plurality of image sensors. The gesture input unitmay detect the user's three-dimensional gesture input based on the TOF,structured light, or disparity principle. The mechanical input unit mayconvert a physical input (e.g., press or rotation) from the user througha mechanical device into an electrical signal. The mechanical input unitmay include at least one of a button, a dome switch, a jog wheel, and ajog switch. Meanwhile, the gesture input unit and the mechanical inputunit may be integrated. For example, the input device 310 may include ajog dial device that includes a gesture sensor and is formed such thatjog dial device may be inserted/ejected into/from a part of asurrounding structure (e.g., at least one of a seat, an armrest, and adoor). When the jog dial device is parallel to the surroundingstructure, the jog dial device may serve as the gesture input unit. Whenthe jog dial device protrudes from the surrounding structure, the jogdial device may serve as the mechanical input unit. The voice input unitmay convert a user's voice input into an electrical signal. The voiceinput unit may include at least one microphone. The voice input unit mayinclude a beamforming MIC.

4) Imaging Device

The imaging device 320 may include at least one camera. The imagingdevice 320 may include at least one of an internal camera and anexternal camera. The internal camera may capture an image of the insideof the cabin. The external camera may capture an image of the outside ofthe vehicle 10. The internal camera may obtain the image of the insideof the cabin. The imaging device 320 may include at least one internalcamera. It is desirable that the imaging device 320 includes as manycameras as the maximum number of passengers in the vehicle 10. Theimaging device 320 may provide an image obtained by the internal camera.The main controller 370 or at least one processor included in the cabinsystem 300 may detect the motion of the user from the image acquired bythe internal camera, generate a signal on the basis of the detectedmotion, and provide the signal to at least one of the display system350, the cargo system 355, the seat system 360, and the payment system365. The external camera may obtain the image of the outside of thevehicle 10. The imaging device 320 may include at least one externalcamera. It is desirable that the imaging device 320 include as manycameras as the maximum number of passenger doors. The imaging device 320may provide an image obtained by the external camera. The maincontroller 370 or at least one processor included in the cabin system300 may acquire user information from the image acquired by the externalcamera. The main controller 370 or at least one processor included inthe cabin system 300 may authenticate the user or obtain informationabout the user body (e.g., height, weight, etc.), information aboutfellow passengers, and information about baggage from the userinformation.

5) Communication Device

The communication device 330 may exchange a signal with an externaldevice wirelessly. The communication device 330 may exchange the signalwith the external device through a network or directly. The externaldevice may include at least one of a server, a mobile terminal, andanother vehicle. The communication device 330 may exchange a signal withat least one user terminal. To perform communication, the communicationdevice 330 may include an antenna and at least one of an RF circuit andelement capable of at least one communication protocol. In someimplementations, the communication device 330 may use a plurality ofcommunication protocols. The communication device 330 may switch thecommunication protocol depending on the distance to a mobile terminal.

For example, the communication device 330 may exchange the signal withthe external device based on the C-V2X technology. The C-V2X technologymay include LTE-based sidelink communication and/or NR-based sidelinkcommunication. Details related to the C-V2X technology will be describedlater.

The communication device 220 may exchange the signal with the externaldevice according to DSRC technology or WAVE standards based on IEEE802.11p PHY/MAC layer technology and IEEE 1609 Network/Transport layertechnology. The DSRC technology (or WAVE standards) is communicationspecifications for providing ITS services through dedicated short-rangecommunication between vehicle-mounted devices or between a road sideunit and a vehicle-mounted device. The DSRC technology may be acommunication scheme that allows the use of a frequency of 5.9 GHz andhas a data transfer rate in the range of 3 Mbps to 27 Mbps. IEEE 802.11pmay be combined with IEEE 1609 to support the DSRC technology (or WAVEstandards).

According to the present disclosure, the communication device 330 mayexchange the signal with the external device according to either theC-V2X technology or the DSRC technology. Alternatively, thecommunication device 330 may exchange the signal with the externaldevice by combining the C-V2X technology and the DSRC technology.

6) Display System

The display system 350 may display a graphic object. The display system350 may include at least one display device. For example, the displaysystem 350 may include a first display device 410 for common use and asecond display device 420 for individual use.

6.1) Common Display Device

The first display device 410 may include at least one display 411 todisplay visual content. The display 411 included in the first displaydevice 410 may be implemented with at least one of a flat display, acurved display, a rollable display, and a flexible display. For example,the first display device 410 may include a first display 411 disposedbehind a seat and configured to be inserted/ejected into/from the cabin,and a first mechanism for moving the first display 411. The firstdisplay 411 may be disposed such that the first display 411 is capableof being inserted/ejected into/from a slot formed in a seat main frame.In some implementations, the first display device 410 may furtherinclude a mechanism for controlling a flexible part. The first display411 may be formed to be flexible, and a flexible part of the firstdisplay 411 may be adjusted depending on the position of the user. Forexample, the first display device 410 may be disposed on the ceiling ofthe cabin and include a second display formed to be rollable and asecond mechanism for rolling and releasing the second display. Thesecond display may be formed such that images may be displayed on bothsides thereof. For example, the first display device 410 may be disposedon the ceiling of the cabin and include a third display formed to beflexible and a third mechanism for bending and unbending the thirddisplay. In some implementations, the display system 350 may furtherinclude at least one processor that provides a control signal to atleast one of the first display device 410 and the second display device420. The processor included in the display system 350 may generate acontrol signal based on a signal received from at last one of the maincontroller 370, the input device 310, the imaging device 320, and thecommunication device 330.

The display area of a display included in the first display device 410may be divided into a first area 411 a and a second area 411 b. Thefirst area 411 a may be defined as a content display area. For example,at least one of graphic objects corresponding to display entertainmentcontent (e.g., movies, sports, shopping, food, etc.), video conferences,food menus, and augmented reality images may be displayed in the firstarea 411. Further, a graphic object corresponding to driving stateinformation about the vehicle 10 may be displayed in the first area 411a. The driving state information may include at least one of informationabout an object outside the vehicle 10, navigation information, andvehicle state information. The object information may include at leastone of information about the presence of the object, information aboutthe location of the object, information about the distance between thevehicle 10 and the object, and information about the relative speed ofthe vehicle 10 with respect to the object. The navigation informationmay include at least one of map information, information about a setdestination, information about a route to the destination, informationabout various objects on the route, lane information, and information onthe current location of the vehicle 10. The vehicle state informationmay include vehicle attitude information, vehicle speed information,vehicle tilt information, vehicle weight information, vehicleorientation information, vehicle battery information, vehicle fuelinformation, vehicle tire pressure information, vehicle steeringinformation, vehicle internal temperature information, vehicle internalhumidity information, pedal position information, vehicle enginetemperature information, etc. The second area 411 b may be defined as auser interface area. For example, an artificial intelligence agentscreen may be displayed in the second area 411 b. In someimplementations, the second area 411 b may be located in an area definedfor a seat frame. In this case, the user may view content displayed inthe second area 411 b between seats. In some implementations, the firstdisplay device 410 may provide hologram content. For example, the firstdisplay device 410 may provide hologram content for each of a pluralityof users so that only a user who requests the content may view thecontent.

6.2) Display Device for Individual Use

The second display device 420 may include at least one display 421. Thesecond display device 420 may provide the display 421 at a position atwhich only each passenger may view display content. For example, thedisplay 421 may be disposed on the armrest of the seat. The seconddisplay device 420 may display a graphic object corresponding topersonal information about the user. The second display device 420 mayinclude as many displays 421 as the maximum number of passengers in thevehicle 10. The second display device 420 may be layered or integratedwith a touch sensor to implement a touch screen. The second displaydevice 420 may display a graphic object for receiving a user input forseat adjustment or indoor temperature adjustment.

7) Cargo System

The cargo system 355 may provide items to the user according to therequest from the user. The cargo system 355 may operate on the basis ofan electrical signal generated by the input device 310 or thecommunication device 330. The cargo system 355 may include a cargo box.The cargo box may include the items and be hidden under the seat. Whenan electrical signal based on a user input is received, the cargo boxmay be exposed to the cabin. The user may select a necessary item fromthe items loaded in the cargo box. The cargo system 355 may include asliding mechanism and an item pop-up mechanism to expose the cargo boxaccording to the user input. The cargo system 355 may include aplurality of cargo boxes to provide various types of items. A weightsensor for determining whether each item is provided may be installed inthe cargo box.

8) Seat System

The seat system 360 may customize the seat for the user. The seat system360 may operate on the basis of an electrical signal generated by theinput device 310 or the communication device 330. The seat system 360may adjust at least one element of the seat by obtaining user body data.The seat system 360 may include a user detection sensor (e.g., pressuresensor) to determine whether the user sits on the seat. The seat system360 may include a plurality of seats for a plurality of users. One ofthe plurality of seats may be disposed to face at least another seat. Atleast two users may sit while facing each other inside the cabin.

9) Payment System

The payment system 365 may provide a payment service to the user. Thepayment system 365 may operate on the basis of an electrical signalgenerated by the input device 310 or the communication device 330. Thepayment system 365 may calculate the price of at least one service usedby the user and request the user to pay the calculated price.

3. C-V2X

A wireless communication system is a multiple access system thatsupports communication of multiple users by sharing available systemresources (a bandwidth, transmission power, etc.). Examples of multipleaccess systems include a CDMA system, an FDMA system, a TDMA system, anOFDMA system, an SC-FDMA system, and an MC-FDMA system.

Sidelink refers to a communication scheme in which a direct link isestablished between user equipments (UEs) and the UEs directly exchangevoice or data without intervention of a base station (BS). The sidelinkis considered as a solution of relieving the BS of the constraint ofrapidly growing data traffic.

Vehicle-to-everything (V2X) is a communication technology in which avehicle exchanges information with another vehicle, a pedestrian, andinfrastructure by wired/wireless communication. V2X may be categorizedinto four types: vehicle-to-vehicle (V2V), vehicle-to-infrastructure(V2I), vehicle-to-network (V2N), and vehicle-to-pedestrian (V2P). V2Xcommunication may be provided via a PC5 interface and/or a Uu interface.

As more and more communication devices demand larger communicationcapacities, there is a need for enhanced mobile broadband communicationrelative to existing RATs. Accordingly, a communication system is underdiscussion, for which services or UEs sensitive to reliability andlatency are considered. The next-generation RAT in which eMBB, MTC, andURLLC are considered is referred to as new RAT or NR. In NR, V2Xcommunication may also be supported.

Techniques described herein may be used in various wireless accesssystems such as code division multiple access (CDMA), frequency divisionmultiple access (FDMA), time division multiple access (TDMA), orthogonalfrequency division multiple access (OFDMA), single carrier-frequencydivision multiple access (SC-FDMA), and so on. CDMA may be implementedas a radio technology such as universal terrestrial radio access (UTRA)or CDMA2000. TDMA may be implemented as a radio technology such asglobal system for mobile communications (GSM)/general packet radioservice (GPRS)/Enhanced Data Rates for GSM Evolution (EDGE). OFDMA maybe implemented as a radio technology such as IEEE 802.11 (Wi-Fi), IEEE802.16 (WiMAX), IEEE 802.20, evolved-UTRA (E-UTRA), or the like. IEEE802.16m is an evolution of IEEE 802.16e, offering backward compatibilitywith an IRRR 802.16e-based system. UTRA is a part of universal mobiletelecommunications system (UMTS). 3^(rd) generation partnership project(3GPP) long term evolution (LTE) is a part of evolved UMTS (E-UMTS)using evolved UTRA (E-UTRA). 3GPP LTE employs OFDMA for downlink (DL)and SC-FDMA for uplink (UL). LTE-advanced (LTE-A) is an evolution of3GPP LTE.

A successor to LTE-A, 5^(th) generation (5G) new radio access technology(NR) is a new clean-state mobile communication system characterized byhigh performance, low latency, and high availability. 5G NR may use allavailable spectral resources including a low frequency band below 1 GHz,an intermediate frequency band between 1 GHz and 10 GHz, and a highfrequency (millimeter) band of 24 GHz or above.

While the following description is given mainly in the context of LTE-Aor 5G NR for the clarity of description, the technical idea of thepresent disclosure is not limited thereto.

FIG. 7 illustrates the structure of an LTE system to which the presentdisclosure is applicable. This may also be called an evolved UMTSterrestrial radio access network (E-UTRAN) or LTE/LTE-A system.

Referring to FIG. 7 , the E-UTRAN includes evolved Node Bs (eNBs) 20which provide a control plane and a user plane to UEs 10. A UE 10 may befixed or mobile, and may also be referred to as a mobile station (MS),user terminal (UT), subscriber station (SS), mobile terminal (MT), orwireless device. An eNB 20 is a fixed station communication with the UE10 and may also be referred to as a base station (BS), a basetransceiver system (BTS), or an access point.

eNBs 20 may be connected to each other via an X2 interface. An eNB 20 isconnected to an evolved packet core (EPC) 39 via an S1 interface. Morespecifically, the eNB 20 is connected to a mobility management entity(MME) via an S1-MME interface and to a serving gateway (S-GW) via anS1-U interface.

The EPC 30 includes an MME, an S-GW, and a packet data network-gateway(P-GW). The MME has access information or capability information aboutUEs, which are mainly used for mobility management of the UEs. The S-GWis a gateway having the E-UTRAN as an end point, and the P-GW is agateway having a packet data network (PDN) as an end point.

Based on the lowest three layers of the open system interconnection(OSI) reference model known in communication systems, the radio protocolstack between a UE and a network may be divided into Layer 1 (L1), Layer2 (L2) and Layer 3 (L3). These layers are defined in pairs between a UEand an Evolved UTRAN (E-UTRAN), for data transmission via the Uuinterface. The physical (PHY) layer at L1 provides an informationtransfer service on physical channels. The radio resource control (RRC)layer at L3 functions to control radio resources between the UE and thenetwork. For this purpose, the RRC layer exchanges RRC messages betweenthe UE and an eNB.

FIG. 8 illustrates a user-plane radio protocol architecture to which thepresent disclosure is applicable.

FIG. 9 illustrates a control-plane radio protocol architecture to whichthe present disclosure is applicable. A user plane is a protocol stackfor user data transmission, and a control plane is a protocol stack forcontrol signal transmission.

Referring to FIGS. 8 and 9 , the PHY layer provides an informationtransfer service to its higher layer on physical channels. The PHY layeris connected to the medium access control (MAC) layer through transportchannels and data is transferred between the MAC layer and the PHY layeron the transport channels. The transport channels are divided accordingto features with which data is transmitted via a radio interface.

Data is transmitted on physical channels between different PHY layers,that is, the PHY layers of a transmitter and a receiver. The physicalchannels may be modulated in orthogonal frequency division multiplexing(OFDM) and use time and frequencies as radio resources.

The MAC layer provides services to a higher layer, radio link control(RLC) on logical channels. The MAC layer provides a function of mappingfrom a plurality of logical channels to a plurality of transportchannels. Further, the MAC layer provides a logical channel multiplexingfunction by mapping a plurality of logical channels to a singletransport channel. A MAC sublayer provides a data transmission serviceon the logical channels.

The RLC layer performs concatenation, segmentation, and reassembly forRLC serving data units (SDUs). In order to guarantee various quality ofservice (QoS) requirements of each radio bearer (RB), the RLC layerprovides three operation modes, transparent mode (TM), unacknowledgedmode (UM), and acknowledged Mode (AM). An AM RLC provides errorcorrection through automatic repeat request (ARQ).

The RRC layer is defined only in the control plane and controls logicalchannels, transport channels, and physical channels in relation toconfiguration, reconfiguration, and release of RBs. An RB refers to alogical path provided by L1 (the PHY layer) and L2 (the MAC layer, theRLC layer, and the packet data convergence protocol (PDCP) layer), fordata transmission between the UE and the network.

The user-plane functions of the PDCP layer include user datatransmission, header compression, and ciphering. The control-planefunctions of the PDCP layer include control-plane data transmission andciphering/integrity protection.

RB establishment amounts to a process of defining radio protocol layersand channel features and configuring specific parameters and operationmethods in order to provide a specific service. RBs may be classifiedinto two types, signaling radio bearer (SRB) and data radio bearer(DRB). The SRB is used as a path in which an RRC message is transmittedon the control plane, whereas the DRB is used as a path in which userdata is transmitted on the user plane.

Once an RRC connection is established between the RRC layer of the UEand the RRC layer of the E-UTRAN, the UE is placed in RRC_CONNECTEDstate, and otherwise, the UE is placed in RRC_IDLE state. In NR,RRC_INACTIVE state is additionally defined. A UE in the RRC_INACTIVEstate may maintain a connection to a core network, while releasing aconnection from an eNB.

DL transport channels carrying data from the network to the UE include abroadcast channel (BCH) on which system information is transmitted and aDL shared channel (DL SCH) on which user traffic or a control message istransmitted. Traffic or a control message of a DL multicast or broadcastservice may be transmitted on the DL-SCH or a DL multicast channel (DLMCH). UL transport channels carrying data from the UE to the networkinclude a random access channel (RACH) on which an initial controlmessage is transmitted and an UL shared channel (UL SCH) on which usertraffic or a control message is transmitted.

The logical channels which are above and mapped to the transportchannels include a broadcast control channel (BCCH), a paging controlchannel (PCCH), a common control channel (CCCH), a multicast controlchannel (MCCH), and a multicast traffic channel (MTCH).

A physical channel includes a plurality of OFDM symbols in the timedomain by a plurality of subcarriers in the frequency domain. Onesubframe includes a plurality of OFDM symbols in the time domain. An RBis a resource allocation unit defined by a plurality of OFDM symbols bya plurality of subcarriers. Further, each subframe may use specificsubcarriers of specific OFDM symbols (e.g., the first OFDM symbol) in acorresponding subframe for a physical DL control channel (PDCCH), thatis, an L1/L2 control channel. A transmission time interval (TTI) is aunit time for subframe transmission.

FIG. 10 illustrates the structure of a NR system to which the presentdisclosure is applicable.

Referring to FIG. 10 , a next generation radio access network (NG-RAN)may include a next generation Node B (gNB) and/or an eNB, which providesuser-plane and control-plane protocol termination to a UE. In FIG. 10 ,the NG-RAN is shown as including only gNBs, by way of example. A gNB andan eNB are connected to each other via an Xn interface. The gNB and theeNB are connected to a 5G core network (5GC) via an NG interface. Morespecifically, the gNB and the eNB are connected to an access andmobility management function (AMF) via an NG-C interface and to a userplane function (UPF) via an NG-U interface.

FIG. 11 illustrates functional split between the NG-RAN and the 5GC towhich the present disclosure is applicable.

Referring to FIG. 11 , a gNB may provide functions including inter-cellradio resource management (RRM), radio admission control, measurementconfiguration and provision, and dynamic resource allocation. The AMFmay provide functions such as non-access stratum (NAS) security andidle-state mobility processing. The UPF may provide functions includingmobility anchoring and protocol data unit (PDU) processing. A sessionmanagement function (SMF) may provide functions including UE Internetprotocol (IP) address allocation and PDU session control.

FIG. 12 illustrates the structure of a NR radio frame to which thepresent disclosure is applicable.

Referring to FIG. 12 , a radio frame may be used for UL transmission andDL transmission in NR. A radio frame is 10 ms in length, and may bedefined by two 5-ms half-frames. An HF may include five 1-ms subframes.A subframe may be divided into one or more slots, and the number ofslots in an SF may be determined according to a subcarrier spacing(SCS). Each slot may include 12 or 14 OFDM(A) symbols according to acyclic prefix (CP).

In a normal CP (NCP) case, each slot may include 14 symbols, whereas inan extended CP (ECP) case, each slot may include 12 symbols. Herein, asymbol may be an OFDM symbol (or CP-OFDM symbol) or an SC-FDMA symbol(or DFT-s-OFDM symbol).

Table 1 below lists the number of symbols per slot N^(slot) _(symb), thenumber of slots per frame N^(frame,u) _(slot), and the number of slotsper subframe N^(suframe,u) _(slot) according to an SCS configuration μin the NCP case.

TABLE 1 SCS (15*2u) N^(slot) _(symb) N^(frame,u) _(slot) N^(subframe,u)_(slot)  15 KHz (u = 0) 14 10 1  30 KHz (u = 1) 14 20 2  60 KHz (u = 2)14 40 4 120 KHz (u = 3) 14 80 8 240 KHz (u = 4) 14 160 16

Table 2 below lists the number of symbols per slot, the number of slotsper frame, and the number of slots per subframe according to an SCS inthe ECP case.

TABLE 2 SCS (15*2{circumflex over ( )}u) N^(slot) _(symb) N^(frame,u)_(slot) N^(subframe,u) _(slot) 60 KHz (u = 2) 12 40 4

In the NR system, different OFDM(A) numerologies (e.g., SCSs, CPlengths, etc.) may be configured for a plurality of cells aggregated forone UE. Thus, the (absolute) duration of a time resource (e.g., SF,slot, or TTI) including the same number of symbols may differ betweenthe aggregated cells (such a time resource is commonly referred to as atime unit (TU) for convenience of description).

FIG. 13 illustrates the slot structure of a NR frame to which thepresent disclosure is applicable.

Referring to FIG. 13 , one slot includes a plurality of symbols in thetime domain. For example, one slot may include 14 symbols in a normal CPand 12 symbols in an extended CP. Alternatively, one slot may include 7symbols in the normal CP and 6 symbols in the extended CP.

A carrier may include a plurality of subcarriers in the frequencydomain. A resource block (RB) is defined as a plurality of consecutivesubcarriers (e.g., 12 subcarriers) in the frequency domain. A bandwidthpart (BWP) may be defined as a plurality of consecutive (P)RBs in thefrequency domain, and the BWP may correspond to one numerology (e.g.,SCS, CP length, etc.). The carrier may include up to N (e.g., 5) BWPs.Data communication may be conducted in an activated BWP. In a resourcegrid, each element is referred to as a resource element (RE), and onecomplex symbol may be mapped thereto.

As shown in FIG. 14 , when transmission resources are selected, thetransmission resource for a next packet may also be reserved.

FIG. 14 illustrates an example of transmission resource selection towhich the present disclosure is applicable.

In V2X communication, transmission may be performed twice for each MACPDU. For example, referring to FIG. 14 , when resources for initialtransmission are selected, resources for retransmission may also bereserved apart from the resources for initial transmission by apredetermined time gap. A UE may identify transmission resourcesreserved or used by other UEs through sensing in a sensing window,exclude the transmission resources from a selection window, and randomlyselect resources with less interference from among the remainingresources.

For example, the UE may decode a physical sidelink control channel(PSCCH) including information about the cycle of reserved resourceswithin the sensing window and measure physical sidelink shared channel(PSSCH) reference signal received power (RSRP) on periodic resourcesdetermined based on the PSCCH. The UE may exclude resources with PSCCHRSRP more than a threshold from the selection window. Thereafter, the UEmay randomly select sidelink resources from the remaining resources inthe selection window.

Alternatively, the UE may measure received signal strength indication(RSSI) for the periodic resources in the sensing window and identifyresources with less interference (for example, the bottom 20 percent).After selecting resources included in the selection window from amongthe periodic resources, the UE may randomly select sidelink resourcesfrom among the resources included in the selection window. For example,when the UE fails to decode the PSCCH, the UE may apply theabove-described method.

FIG. 15 illustrates an example of PSCCH transmission in sidelinktransmission mode 3 or 4 to which the present disclosure is applicable.

In V2X communication, that is, in sidelink transmission mode 3 or 4, aPSCCH and a PSSCH are frequency division multiplexed (FDM) andtransmitted, unlike sidelink communication. Since latency reduction isimportant in V2X in consideration of the nature of vehiclecommunication, the PSCCH and PSSCH are FDM and transmitted on the sametime resources but different frequency resources. Referring to FIG. 15 ,the PSCCH and PSSCH may not be contiguous to each other as illustratedin FIG. 15 (a) or may be contiguous to each other as illustrated in FIG.15 (b). A subchannel is used as a basic transmission unit. Thesubchannel may be a resource unit including one or more RBs in thefrequency domain within a predetermined time resource (e.g., timeresource unit). The number of RBs included in the subchannel (i.e., thesize of the subchannel and the starting position of the subchannel inthe frequency domain) may be indicated by higher layer signaling. Theexample of FIG. 15 may be applied to NR sidelink resource allocationmode 1 or 2.

Hereinafter, a cooperative awareness message (CAM) and a decentralizedenvironmental notification message (DENM) will be described.

In V2V communication, a periodic message type of CAM and anevent-triggered type of DENM may be transmitted. The CAM may includedynamic state information about a vehicle such as direction and speed,vehicle static data such as dimensions, and basic vehicle informationsuch as ambient illumination states, path details, etc. The CAM may be50 to 300 bytes long. In addition, the CAM is broadcast, and the latencythereof should be less than 100 ms. The DENM may be generated upon theoccurrence of an unexpected incident such as a breakdown, an accident,etc. The DENM may be shorter than 3000 bytes, and it may be received byall vehicles within the transmission range thereof. The DENM may beprioritized over the CAM.

Hereinafter, carrier reselection will be described.

The carrier reselection for V2X/sidelink communication may be performedby MAC layers based on the channel busy ratio (CBR) of configuredcarriers and the ProSe per-packet priority (PPPP) of a V2X message to betransmitted.

The CBR may refer to a portion of sub-channels in a resource pool whereS-RSSI measured by the UE is greater than a preconfigured threshold.There may be a PPPP related to each logical channel, and latencyrequired by both the UE and BS needs to be reflected when the PPPP isconfigured. In the carrier reselection, the UE may select at least onecarrier among candidate carriers in ascending order from the lowest CBR.

Hereinafter, physical layer processing will be described.

A transmitting side may perform the physical layer processing on a dataunit to which the present disclosure is applicable before transmittingthe data unit over an air interface, and a receiving side may performthe physical layer processing on a radio signal carrying the data unitto which the present disclosure is applicable.

FIG. 16 illustrates physical layer processing at a transmitting side towhich the present disclosure is applicable.

Table 3 shows a mapping relationship between UL transport channels andphysical channels, and Table 4 shows a mapping relationship between ULcontrol channel information and physical channels.

TABLE 3 Transport channel Physical channel UL-SCH PUSCH RACH PRACH

TABLE 4 Control information Physical channel UCI PUCCH, PUSCH

Table 5 shows a mapping relationship between DL transport channels andphysical channels, and Table 6 shows a mapping relationship between DLcontrol channel information and physical channels.

TABLE 5 Transport channel Transport channel DL-SCH PDSCH BCH PBCH PCHPDSCH

TABLE 6 Control information Physical channel DCI PDCCH

Table 7 shows a mapping relationship between sidelink transport channelsand physical channels, and Table 8 shows a mapping relationship betweensidelink control channel information and physical channels.

TABLE 7 Transport channel Transport channel SL-SCH PSSCH SL-BCH PSBCH

TABLE 8 Control information Transport channel SCI PSCCH

Referring to FIG. 17 , a transmitting side may encode a TB in step S100.The PHY layer may encode data and a control stream from the MAC layer toprovide transport and control services via a radio transmission link inthe PHY layer. For example, a TB from the MAC layer may be encoded to acodeword at the transmitting side. A channel coding scheme may be acombination of error detection, error correction, rate matching,interleaving, and control information or a transport channel demappedfrom a physical channel. Alternatively, a channel coding scheme may be acombination of error detection, error correcting, rate matching,interleaving, and control information or a transport channel mapped to aphysical channel.

In the NR LTE system, the following channel coding schemes may be usedfor different types of transport channels and different types of controlinformation. For example, channel coding schemes for respectivetransport channel types may be listed as in Table 9. For example,channel coding schemes for respective control information types may belisted as in Table 10.

TABLE 9 Transport channel Channel coding scheme UL-SCH LDPC DL-SCH (LowDensity Parity Check) SL-SCH PCH BCH Polar code SL-BCH

TABLE 10 Control information Channel coding scheme DCI Polar code SCIUCI Block code, Polar code

For transmission of a TB (e.g., a MAC PDU), the transmitting side mayattach a CRC sequence to the TB. Thus, the transmitting side may provideerror detection for the receiving side. In sidelink communication, thetransmitting side may be a transmitting UE, and the receiving side maybe a receiving UE. In the NR system, a communication device may use anLDPC code to encode/decode a UL-SCH and a DL-SCH. The NR system maysupport two LDPC base graphs (i.e., two LDPC base metrics). The two LDPCbase graphs may be LDPC base graph 1 optimized for a small TB and LDPCbase graph 2 optimized for a large TB. The transmitting side may selectLDPC base graph 1 or LDPC base graph 2 based on the size and coding rateR of a TB. The coding rate may be indicated by an MCS index, I_MCS. TheMCS index may be dynamically provided to the UE by a PDCCH thatschedules a PUSCH or PDSCH. Alternatively, the MCS index may bedynamically provided to the UE by a PDCCH that (re)initializes oractivates UL configured grant type 2 or DL semi-persistent scheduling(SPS). The MCS index may be provided to the UE by RRC signaling relatedto UL configured grant type 1. When the TB attached with the CRC islarger than a maximum code block (CB) size for the selected LDPC basegraph, the transmitting side may divide the TB attached with the CRCinto a plurality of CBs. The transmitting side may further attach anadditional CRC sequence to each CB. The maximum code block sizes forLDPC base graph 1 and LDPC base graph 2 may be 8448 bits and 3480 bits,respectively. When the TB attached with the CRC is not larger than themaximum CB size for the selected LDPC base graph, the transmitting sidemay encode the TB attached with the CRC to the selected LDPC base graph.The transmitting side may encode each CB of the TB to the selected LDPCbasic graph. The LDPC CBs may be rate-matched individually. The CBs maybe concatenated to generate a codeword for transmission on a PDSCH or aPUSCH. Up to two codewords (i.e., up to two TBs) may be transmittedsimultaneously on the PDSCH. The PUSCH may be used for transmission ofUL-SCH data and layer-1 and/or layer-2 control information. While notshown in FIG. 16 , layer-1 and/or layer-2 control information may bemultiplexed with a codeword for UL-SCH data.

In steps S101 and S102, the transmitting side may scramble and modulatethe codeword. The bits of the codeword may be scrambled and modulated toproduce a block of complex-valued modulation symbols.

In step S103, the transmitting side may perform layer mapping. Thecomplex-valued modulation symbols of the codeword may be mapped to oneor more MIMO layers. The codeword may be mapped to up to four layers.The PDSCH may carry two codewords, thus supporting up to 8-layertransmission. The PUSCH may support a single codeword, thus supportingup to 4-layer transmission.

In step S104, the transmitting side may perform precoding transform. ADL transmission waveform may be general OFDM using a CP. For DL,transform precoding (i.e., discrete Fourier transform (DFT)) may not beapplied.

A UL transmission waveform may be conventional OFDM using a CP having atransform precoding function that performs DFT spreading which may bedisabled or enabled. In the NR system, transform precoding, if enabled,may be selectively applied to UL. Transform precoding may be to spreadUL data in a special way to reduce the PAPR of the waveform. Transformprecoding may be a kind of DFT. That is, the NR system may support twooptions for the UL waveform. One of the two options may be CP-OFDM (sameas DL waveform) and the other may be DFT-s-OFDM. Whether the UE shoulduse CP-OFDM or DFT-s-OFDM may be determined by the BS through an RRCparameter.

In step S105, the transmitting side may perform subcarrier mapping. Alayer may be mapped to an antenna port. In DL, transparent(non-codebook-based) mapping may be supported for layer-to-antenna portmapping, and how beamforming or MIMO precoding is performed may betransparent to the UE. In UL, both non-codebook-based mapping andcodebook-based mapping may be supported for layer-to-antenna portmapping.

For each antenna port (i.e. layer) used for transmission of a physicalchannel (e.g. PDSCH, PUSCH, or PSSCH), the transmitting side may mapcomplex-valued modulation symbols to subcarriers in an RB allocated tothe physical channel.

In step S106, the transmitting side may perform OFDM modulation. Acommunication device of the transmitting side may add a CP and performinverse fast Fourier transform (IFFT), thereby generating atime-continuous OFDM baseband signal on an antenna port p and asubcarrier spacing configuration u for an OFDM symbol 1 within a TTI forthe physical channel. For example, for each OFDM symbol, thecommunication device of the transmitting side may perform IFFT on acomplex-valued modulation symbol mapped to an RB of the correspondingOFDM symbol. The communication device of the transmitting side may add aCP to the IFFT signal to generate an OFDM baseband signal.

In step S107, the transmitting side may perform up-conversion. Thecommunication device of the transmitting side may upconvert the OFDMbaseband signal, the SCS configuration u, and the OFDM symbol 1 for theantenna port p to a carrier frequency f0 of a cell to which the physicalchannel is allocated.

Processors 102 and 202 of FIG. 23 may be configured to perform encoding,scrambling, modulation, layer mapping, precoding transformation (forUL), subcarrier mapping, and OFDM modulation.

FIG. 17 illustrates PHY-layer processing at a receiving side to whichthe present disclosure is applicable.

The PHY-layer processing of the receiving side may be basically thereverse processing of the PHY-layer processing of a transmitting side.

In step S110, the receiving side may perform frequency downconversion. Acommunication device of the receiving side may receive a radio frequency(RF) signal in a carrier frequency through an antenna. A transceiver 106or 206 that receives the RF signal in the carrier frequency maydownconvert the carrier frequency of the RF signal to a baseband toobtain an OFDM baseband signal.

In step S111, the receiving side may perform OFDM demodulation. Thecommunication device of the receiving side may acquire complex-valuedmodulation symbols by CP detachment and fast Fourier transform (FFT).For example, for each OFDM symbol, the communication device of thereceiving side may remove a CP from the OFDM baseband signal. Thecommunication device of the receiving side may then perform FFT on theCP-free OFDM baseband signal to obtain complex-valued modulation symbolsfor an antenna port p, an SCS u, and an OFDM symbol 1.

In step S112, the receiving side may perform subcarrier demapping.Subcarrier demapping may be performed on the complex-valued modulationsymbols to obtain complex-valued modulation symbols of the physicalchannel. For example, the processor of a UE may obtain complex-valuedmodulation symbols mapped to subcarriers of a PDSCH among complex-valuedmodulation symbols received in a BWP.

In step S113, the receiving side may perform transform de-precoding.When transform precoding is enabled for a UL physical channel, transformde-precoding (e.g., inverse discrete Fourier transform (IDFT)) may beperformed on complex-valued modulation symbols of the UL physicalchannel. Transform de-precoding may not be performed for a DL physicalchannel and a UL physical channel for which transform precoding isdisabled.

In step S114, the receiving side may perform layer demapping. Thecomplex-valued modulation symbols may be demapped into one or twocodewords.

In steps S115 and S116, the receiving side may perform demodulation anddescrambling. The complex-valued modulation symbols of the codewords maybe demodulated and descrambled into bits of the codewords.

In step S117, the receiving side may perform decoding. The codewords maybe decoded into TBs. For a UL-SCH and a DL-SCH, LDPC base graph 1 orLDPC base graph 2 may be selected based on the size and coding rate R ofa TB. A codeword may include one or more CBs. Each coded block may bedecoded into a CB to which a CRC has been attached or a TB to which aCRC has been attached, by the selected LDPC base graph. When CBsegmentation has been performed for the TB attached with the CRC at thetransmitting side, a CRC sequence may be removed from each of the CBseach attached with a CRC, thus obtaining CBs. The CBs may beconcatenated to a TB attached with a CRC. A TB CRC sequence may beremoved from the TB attached with the CRC, thereby obtaining the TB. TheTB may be delivered to the MAC layer.

Each of processors 102 and 202 of FIG. 22 may be configured to performOFDM demodulation, subcarrier demapping, layer demapping, demodulation,descrambling, and decoding.

In the above-described PHY-layer processing on thetransmitting/receiving side, time and frequency resources (e.g., OFDMsymbol, subcarrier, and carrier frequency) related to subcarriermapping, OFDM modulation, and frequency upconversion/downconversion maybe determined based on a resource allocation (e.g., an UL grant or a DLassignment).

Synchronization acquisition of a sidelink UE will be described below.

In TDMA and FDMA systems, accurate time and frequency synchronization isessential. Inaccurate time and frequency synchronization may lead todegradation of system performance due to inter-symbol interference (ISI)and inter-carrier interference (ICI). The same is true for V2X. Fortime/frequency synchronization in V2X, a sidelink synchronization signal(SLSS) may be used in the PHY layer, and master informationblock-sidelink-V2X (MIB-SL-V2X) may be used in the RLC layer.

FIG. 18 illustrates a V2X synchronization source or reference to whichthe present disclosure is applicable.

Referring to FIG. 18 , in V2X, a UE may be synchronized with a GNSSdirectly or indirectly through a UE (within or out of network coverage)directly synchronized with the GNSS. When the GNSS is configured as asynchronization source, the UE may calculate a direct subframe number(DFN) and a subframe number by using a coordinated universal time (UTC)and a (pre)determined DFN offset.

Alternatively, the UE may be synchronized with a BS directly or withanother UE which has been time/frequency synchronized with the BS. Forexample, the BS may be an eNB or a gNB. For example, when the UE is innetwork coverage, the UE may receive synchronization informationprovided by the BS and may be directly synchronized with the BS.Thereafter, the UE may provide synchronization information to anotherneighboring UE. When a BS timing is set as a synchronization reference,the UE may follow a cell associated with a corresponding frequency (whenwithin the cell coverage in the frequency), a primary cell, or a servingcell (when out of cell coverage in the frequency), for synchronizationand DL measurement.

The BS (e.g., serving cell) may provide a synchronization configurationfor a carrier used for V2X or sidelink communication. In this case, theUE may follow the synchronization configuration received from the BS.When the UE fails in detecting any cell in the carrier used for the V2Xor sidelink communication and receiving the synchronizationconfiguration from the serving cell, the UE may follow a predeterminedsynchronization configuration.

Alternatively, the UE may be synchronized with another UE which has notobtained synchronization information directly or indirectly from the BSor GNSS. A synchronization source and a preference may be preset for theUE. Alternatively, the synchronization source and the preference may beconfigured for the UE by a control message provided by the BS.

A sidelink synchronization source may be related to a synchronizationpriority. For example, the relationship between synchronization sourcesand synchronization priorities may be defined as shown in Table 11.Table 11 is merely an example, and the relationship betweensynchronization sources and synchronization priorities may be defined invarious manners.

TABLE 11 GNSS-based BS-based synchronization Priority synchronization(eNB/gNB-based synchronization) P0 GNSS BS P1 All UEs directly All UEsdirectly synchronized with GNSS synchronized with BS P2 All UEsindirectly All UEs indirectly synchronized with GNSS synchronized withBS P3 All other UEs GNSS P4 N/A All UEs directly synchronized with GNSSP5 N/A All UEs indirectly synchronized with GNSS P6 N/A All other UEs

Whether to use GNSS-based synchronization or BS-based synchronizationmay be (pre)determined. In a single-carrier operation, the UE may deriveits transmission timing from an available synchronization reference withthe highest priority.

In the conventional sidelink communication, the GNSS, eNB, and UE may beset/selected as the synchronization reference as described above. In NR,the gNB has been introduced so that the NR gNB may become thesynchronization reference as well. However, in this case, thesynchronization source priority of the gNB needs to be determined. Inaddition, a NR UE may neither have an LTE synchronization signaldetector nor access an LTE carrier (non-standalone NR UE). In thissituation, the timing of the NR UE may be different from that of an LTEUE, which is not desirable from the perspective of effective resourceallocation. For example, if the LTE UE and NR UE operate at differenttimings, one TTI may partially overlap, resulting in unstableinterference therebetween, or some (overlapping) TTIs may not be usedfor transmission and reception. To this end, various implementations forconfiguring the synchronization reference when the NR gNB and LTE eNBcoexist will be described based on the above discussion. Herein, thesynchronization source/reference may be defined as a synchronizationsignal used by the UE to transmit and receive a sidelink signal orderive a timing for determining a subframe boundary. Alternatively, thesynchronization source/reference may be defined as a subject thattransmits the synchronization signal. If the UE receives a GNSS signaland determines the subframe boundary based on a UTC timing derived fromthe GNSS, the GNSS signal or GNSS may be the synchronizationsource/reference.

In the conventional sidelink communication, the GNSS, eNB, and UE may beset/selected as the synchronization reference as described above. In NR,the gNB has been introduced so that the NR gNB may become thesynchronization reference as well. However, in this case, thesynchronization source priority of the gNB needs to be determined. Inaddition, a NR UE may neither have an LTE synchronization signaldetector nor access an LTE carrier (non-standalone NR UE). In thissituation, the timing of the NR UE may be different from that of an LTEUE, which is not desirable from the perspective of effective resourceallocation. For example, if the LTE UE and NR UE operate at differenttimings, one TTI may partially overlap, resulting in unstableinterference therebetween, or some (overlapping) TTIs may not be usedfor transmission and reception. To this end, various implementations forconfiguring the synchronization reference when the NR gNB and LTE eNBcoexist will be described based on the above discussion. Herein, thesynchronization source/reference may be defined as a synchronizationsignal used by the UE to transmit and receive a sidelink signal orderive a timing for determining a subframe boundary. Alternatively, thesynchronization source/reference may be defined as a subject thattransmits the synchronization signal. If the UE receives a GNSS signaland determines the subframe boundary based on a UTC timing derived fromthe GNSS, the GNSS signal or GNSS may be the synchronizationsource/reference.

Initial access (IA)

For a process in which the base station and the terminal are connected,the base station and the terminal (transmitting/receiving terminal) mayperform an initial access (IA) operation.

Cell Search

Cell search is the procedure by which a UE acquires time and frequencysynchronization with a cell and detects the physical layer Cell ID ofthat cell. A UE receives the following synchronization signals (SS) inorder to perform cell search: the primary synchronization signal (PSS)and secondary synchronization signal (SSS).

A UE shall assume that reception occasions of a physical broadcastchannel (PBCH), PSS, and SSS are in consecutive symbols and form aSS/PBCH block. The UE shall assume that SSS, PBCH DM-RS, and PBCH datahave the same EPRE. The UE may assume that the ratio of PSS EPRE to SSSEPRE in a SS/PBCH block in a corresponding cell is either 0 dB or 3 dB.

The cell search procedure of the UE can be summarized in Table 12.

TABLE 12 Type of Signals Operations 1^(st) PSS * SS/PBCH block (SSB)symbol timing step acquisition * Cell ID detection within a cell IDgroup (3 hypothesis) 2^(nd) SSS * Cell ID group detection (336hypothesis) Step 3^(rd) PBCH DMRS * SSB index and Half frame index (Slotand Step frame boundary detection) 4^(th) PBCH * Time information (80ms, SFN, SSB index, Step HF) * RMSI CORESET/Search space configuration5^(th) PDCCH and PDSCH * Cell access information * RACH Stepconfiguration

The synchronization signal and PBCH block consists of primary andsecondary synchronization signals (PSS, SSS), each occupying 1 symboland 127 subcarriers, and PBCH spanning across 3 OFDM symbols and 240subcarriers, but on one symbol leaving an unused part in the middle forSSS as show in the following FIG. 19 . The periodicity of the SS/PBCHblock can be configured by the network and the time locations whereSS/PBCH block can be sent are determined by sub-carrier spacing.

Polar coding is used for PBCH. The UE may assume a band-specificsub-carrier spacing for the SS/PBCH block unless a network hasconfigured the UE to assume a different sub-carrier spacing.

PBCH symbols carry its own frequency-multiplexed DMRS. QPSK modulationis used for PBCH.

There are 1008 unique physical-layer cell identities given by:N _(ID) ^(cell)=3N _(ID) ⁽¹⁾ +N _(ID) ⁽²⁾  [Equation 1]

where N_(ID) ⁽¹⁾∈{0, 1, . . . , 335} and N_(ID) ⁽²⁾∈{0, 1, 2}.

The PSS sequence d_(PSS)(n) for the primary synchronization signal isdefined by:

$\begin{matrix}{\mspace{76mu}{{{d_{PSS}(n)} = {1 - {2{x(m)}}}}\mspace{76mu}{m = {( {n + {43N_{ID}^{(2)}}} ){mod}\; 27}}\mspace{76mu}{0 \leq n < 127}\mspace{76mu}{{{where}\mspace{14mu}{x( {i + 7} )}} = {{( {{x( {i + 4} )} + {x(i)}} ){mod}\; 2\mspace{14mu}{{and}\lbrack {{x(6)}\mspace{14mu}{x(5)}\mspace{14mu}{x(4)}\mspace{14mu}{x(3)}\mspace{14mu}{x(2)}\mspace{14mu}{x(1)}\mspace{14mu}{x(0)}} \rbrack}} = \lbrack {1\mspace{14mu} 1\mspace{14mu} 1\mspace{14mu} 0\mspace{14mu} 1\mspace{14mu} 1\mspace{14mu} 0} \rbrack}}}} & \lbrack {{Equation}\mspace{14mu} 2} \rbrack \\{{d_{SSS}(n)} = {\lbrack {1 - {2{x_{0}( {( {n + m_{0}} ){mod}\; 127} )}}} \rbrack{\quad{{\lbrack {1 - {2{x_{1}( {( {n + m_{1}} ){mod}\; 127} )}}} \rbrack\mspace{76mu} m_{0}} = {{{15\lfloor \frac{N_{ID}^{(1)}}{112} \rfloor} + {5N_{ID}^{(2)}\mspace{76mu} m_{1}}} = {{{N_{ID}^{(1)}{mod}\; 112\mspace{76mu} 0} \leq n < {127\mspace{76mu}{where}\mspace{76mu}{x_{0}( {i + 7} )}}} = {{( {{x_{0}( {i + 4} )} + {x_{0}(i)}} ){mod}\; 2\mspace{76mu}{x_{1}( {i + 7} )}} = {{( {{x_{1}( {i + 1} )} + {x_{i}(i)}} ){mod}\; 2\mspace{14mu}{{and}\lbrack {{x_{0}(6)}\mspace{14mu}{x_{0}(5)}\mspace{14mu}{x_{0}(4)}\mspace{14mu}{x_{0}(3)}\mspace{14mu}{x_{0}(2)}\mspace{14mu}{x_{0}(1)}\mspace{14mu}{x_{0}(0)}} \rbrack}} = {\quad{{\lbrack {0\mspace{14mu} 0\mspace{14mu} 0\mspace{14mu} 0\mspace{14mu} 0\mspace{14mu} 0\mspace{14mu} 1} \rbrack\lbrack {{x_{1}(6)}\mspace{14mu}{x_{1}(5)}\mspace{14mu}{x_{1}(4)}\mspace{14mu}{x_{1}(3)}\mspace{14mu}{x_{1}(2)}\mspace{14mu}{x_{1}(1)}\mspace{14mu}{x_{1}(0)}} \rbrack} = {\quad\lbrack {0\mspace{14mu} 0\mspace{14mu} 0\mspace{14mu} 0\mspace{14mu} 0\mspace{14mu} 0\mspace{14mu} 1} \rbrack}}}}}}}}}}} & \lbrack {{Equation}\mspace{14mu} 3} \rbrack\end{matrix}$

This sequence is mapped to the physical resource as illustrated in FIG.19 .

For a half frame with SS/PBCH blocks, the first symbol indexes forcandidate SS/PBCH blocks are determined according to the subcarrierspacing of SS/PBCH blocks as follows.

-   -   Case A—15 kHz subcarrier spacing: the first symbols of the        candidate SS/PBCH blocks have indexes of {2, 8}+14*n. For        carrier frequencies smaller than or equal to 3 GHz, n=0, 1. For        carrier frequencies larger than 3 GHz and smaller than or equal        to 6 GHz, n=0, 1, 2, 3.    -   Case B—30 kHz subcarrier spacing: the first symbols of the        candidate SS/PBCH blocks have indexes {4, 8, 16, 20}+28*n. For        carrier frequencies smaller than or equal to 3 GHz, n=0. For        carrier frequencies larger than 3 GHz and smaller than or equal        to 6 GHz, n=0, 1.    -   Case C—30 kHz subcarrier spacing: the first symbols of the        candidate SS/PBCH blocks have indexes {2, 8}+14*n. For carrier        frequencies smaller than or equal to 3 GHz, n=0, 1. For carrier        frequencies larger than 3 GHz and smaller than or equal to 6        GHz, n=0, 1, 2, 3.    -   Case D—120 kHz subcarrier spacing: the first symbols of the        candidate SS/PBCH blocks have indexes {4, 8, 16, 20}+28*n. For        carrier frequencies larger than 6 GHz, n=0, 1, 2, 3, 5, 6, 7, 8,        10, 11, 12, 13, 15, 16, 17, 18.    -   Case E—240 kHz subcarrier spacing: the first symbols of the        candidate SS/PBCH blocks have indexes {8, 12, 16, 20, 32, 36,        40, 44}+56*n. For carrier frequencies larger than 6 GHz, n=0, 1,        2, 3, 5, 6, 7, 8.

The candidate SS/PBCH blocks in a half frame are indexed in an ascendingorder in time from 0 to L−1. A UE shall determine the 2 LSB bits, forL=4, or the 3 LSB bits, for L>4, of a SS/PBCH block index per half framefrom a one-to-one mapping with an index of the DM-RS sequencetransmitted in the PBCH. For L=64, the UE shall determine the 3 MSB bitsof the SS/PBCH block index per half frame by PBCH payload bits ā_(Ā+5) ,ā_(Ā+6) , ā_(Ā+7) .

A UE can be configured by higher layer parameter SSB-transmitted-SIB1,indexes of SS/PBCH blocks for which the UE shall not receive othersignals or channels in REs that overlap with REs corresponding to theSS/PBCH blocks. A UE can also be configured per serving cell, by higherlayer parameter SSB-transmitted, indexes of SS/PBCH blocks for which theUE shall not receive other signals or channels in REs that overlap withREs corresponding to the SS/PBCH blocks. A configuration bySSB-transmitted overrides a configuration by SSB-transmitted-SIB 1. A UEcan be configured per serving cell by higher layer parameterSSB-periodicityServingCell a periodicity of the half frames forreception of SS/PBCH blocks per serving cell. If the UE is notconfigured a periodicity of the half frames for receptions of SS/PBCHblocks, the UE shall assume a periodicity of a half frame. A UE shallassume that the periodicity is same for all SS/PBCH blocks in theserving cell.

FIG. 20 shows how the UE acquires timing information according to oneembodiment.

Firstly, the UE may acquire 6 bits SFN information via MIB(MasterInformationBlock) received in the PBCH. Also, 4 bits of SFN canbe acquired in the PBCH transport block.

Secondly, the UE may acquire one-bit half frame indication as a part ofPBCH payload. For below 3 GHz, half frame indication is furtherimplicitly signalled as part of PBCH DMRS for Lmax=4.

Lastly, the UE may acquire SS/PBCH block index by DMRS sequence and PBCHpayload. That is, LSB 3 bits of SS block index is acquired by DMRSsequence within 5 ms period. And, MSB 3 bit of the timing informationare carried explicitly in the PBCH payload (for above 6 GHz).

For initial cell selection, a UE may assume that half frames withSS/PBCH blocks occur with a periodicity of 2 frames. Upon detection of aSS/PBCH block, the UE determines that a control resource set forType0-PDCCH common search space is present if k_(SSB)≤23 for FR1 and ifk_(SSB)≤11 for FR2. The UE determines that a control resource set forType0-PDCCH common search space is not present if k_(SSB)>23 k for FR1and if k_(SSB)>11 for FR2.

For a serving cell without transmission of SS/PBCH blocks, a UE acquirestime and frequency synchronization with the serving cell based onreceptions of SS/PBCH blocks on the PCell, or on the PSCell, of the cellgroup for the serving cell.

System Information Acquisition

System Information (SI) is divided into the MasterInformationBlock (MIB)and a number of SystemInformationBlocks (SIBs) where:

-   -   the MasterInformationBlock (MIB) is always transmitted on the        BCH with a periodicity of 80 ms and repetitions made within 80        ms and it includes parameters that are needed to acquire        SystemInformationBlockType1 (SIB1) from the cell;    -   the SystemInformationBlockType1 (SIB1) is transmitted on the        DL-SCH with a periodicity and repetitions. SIB1 includes        information regarding the availability and scheduling (e.g.        periodicity, SI-window size) of other SIBs. It also indicates        whether they (i.e. other SIBs) are provided via periodic        broadcast basis or only on-demand basis. If other SIBs are        provided on-demand then SIB1 includes information for the UE to        perform SI request;    -   SIs other than SystemInformationBlockType1 are carried in        SystemInformation (SI) messages, which are transmitted on the        DL-SCH. Each SI message is transmitted within periodically        occurring time domain windows (referred to as SI-windows);    -   For PSCell and SCells, RAN provides the required SI by dedicated        signalling. Nevertheless, the UE shall acquire MIB of the PSCell        to get SFN timing of the SCG (which may be different from MCG).        Upon change of relevant SI for SCell, RAN releases and adds the        concerned SCell. For PSCell, SI can only be changed with        Reconfiguration with Sync.

The UE applies the SI acquisition procedure to acquire the AS- and NASinformation. The procedure applies to UEs in RRC_IDLE, in RRC_INACTIVEand in RRC_CONNECTED.

The UE in RRC_IDLE and RRC_INACTIVE shall ensure having a valid versionof (at least) the MasterinformationBlock, SystemInformationBlockType1 aswell as SystemInformationBlockTypeX through SystemInformationBlockTypeY(depending on support of the concerned RATs for UE controlled mobility).

The UE in RRC_CONNECTED shall ensure having a valid version of (atleast) the MasterinformationBlock, SystemInformationBlockType1 as wellas SystemInformationBlockTypeX (depending on support of mobility towardsthe concerned RATs).

The UE shall store relevant SI acquired from the currentlycamped/serving cell. A version of the SI that the UE acquires and storesremains valid only for a certain time. The UE may use such a storedversion of the SI e.g. after cell re-selection, upon return from out ofcoverage or after SI change indication.

Random Access

The random access procedure of the UE can be summarized in Table 13 andFIG. 22 .

TABLE 13 Type of Signals Operations/Information Acquired 1st PRACHpreamble * Initial beam acquisition Step in UL * Random election ofRA-preamble ID 2nd Random Access * Timing alignment information StepResponse on DL-SCH * RA-preamble ID * Initial UL grant, Temporary C-RNTI3rd UL transmission on * RRC connection request Step UL-SCH * UEidentifier 4th Contention Resolution * Temporary C-RNTI on PDCCH forStep on DL initial access * C-RNTI on PDCCH for UE in RRC_CONNECTED

Firstly, the UE may transmit PRACH preamble in UL as Msg1 of the randomaccess procedure.

Random access preamble sequences, of two different lengths aresupported. Long sequence length 839 is applied with subcarrier spacingsof 1.25 and 5 kHz and short sequence length 139 is applied withsub-carrier spacings 15, 30, 60 and 120 kHz. Long sequences supportunrestricted sets and restricted sets of Type A and Type B, while shortsequences support unrestricted sets only.

Multiple RACH preamble formats are defined with one or more RACH OFDMsymbols, and different cyclic prefix and guard time. The PRACH preambleconfiguration to use is provided to the UE in the system information.

When there is no response to the Msg1, the UE may retransmit the PRACHpreamble with power rampling within the prescribed number of times. TheUE calculates the PRACH transmit power for the retransmission of thepreamble based on the most recent estimate pathloss and power rampingcounter. If the UE conducts beam switching, the counter of power rampingremains unchanged.

The system information informs the UE of the association between the SSblocks and the RACH resources. FIG. 23 below shows the concept ofthreshold of the SS block for RACH resource association.

The threshold of the SS block for RACH resource association is based onthe RSRP and network configurable. Transmission or retransmission ofRACH preamble is based on the SS blocks that satisfy the threshold.

When the UE receives random access response on DL-SCH, the DL-SCH mayprovide timing alignment information, RA-preamble ID, initial UL grantand Temporary C-RNTI.

Based on this information, the UE may transmit UL transmission on UL-SCHas Msg3 of the random access procedure. Msg3 can include RRC connectionrequest and UE identifier.

In response, the network may transmit Msg4, which can be treated ascontention resolution message on DL. By receiving this, the UE may enterinto RRC connected state.

Specific explanation for each of the steps is as follows:

Prior to initiation of the physical random access procedure, Layer 1shall receive from higher layers a set of SS/PBCH block indexes andshall provide to higher layers a corresponding set of RSRP measurements.

Prior to initiation of the physical random access procedure, Layer 1shall receive the following information from the higher layers:

-   -   Configuration of physical random access channel (PRACH)        transmission parameters (PRACH preamble format, time resources,        and frequency resources for PRACH transmission).    -   Parameters for determining the root sequences and their cyclic        shifts in the PRACH preamble sequence set (index to logical root        sequence table, cyclic shift (N_(CS)), and set type        (unrestricted, restricted set A, or restricted set B)).

From the physical layer perspective, the L1 random access procedureencompasses the transmission of random access preamble (Msg1) in aPRACH, random access response (RAR) message with a PDCCH/PDSCH (Msg2),and when applicable, the transmission of Msg3 PUSCH, and PDSCH forcontention resolution.

If a random access procedure is initiated by a “PDCCH order” to the UE,a random access preamble transmission is with a same subcarrier spacingas a random access preamble transmission initiated by higher layers.

If a UE is configured with two UL carriers for a serving cell and the UEdetects a “PDCCH order”, the UE uses the UL/SUL indicator field valuefrom the detected “PDCCH order” to determine the UL carrier for thecorresponding random access preamble transmission.

Regarding the random access preamble transmission step, physical randomaccess procedure is triggered upon request of a PRACH transmission byhigher layers or by a PDCCH order. A configuration by higher layers fora PRACH transmission includes the following:

-   -   A configuration for PRACH transmission.    -   A preamble index, a preamble subcarrier spacing,        P_(PRACHtarget), a corresponding RA-RNTI, and a PRACH resource.

A preamble is transmitted using the selected PRACH format withtransmission power P_(PRACHb,f,c)(i), on the indicated PRACH resource.

A UE is provided a number of SS/PBCH blocks associated with one PRACHoccasion by the value of higher layer parameter SSB-perRACH-Occasion. Ifthe value of SSB-perRACH-Occasion is smaller than one, one SS/PBCH blockis mapped to 1/SSB-per-rach-occasion consecutive PRACH occasions. The UEis provided a number of preambles per SS/PBCH block by the value ofhigher layer parameter cb-preamblePerSSB and the UE determines a totalnumber of preambles per SSB per PRACH occasion as the multiple of thevalue of SSB-perRACH-Occasion and the value of cb-preamblePerSSB.

SS/PBCH block indexes are mapped to PRACH occasions in the followingorder.

-   -   First, in increasing order of preamble indexes within a single        PRACH occasion.    -   Second, in increasing order of frequency resource indexes for        frequency multiplexed PRACH occasions.    -   Third, in increasing order of time resource indexes for time        multiplexed PRACH occasions within a PRACH slot.    -   Fourth, in increasing order of indexes for PRACH slots.

The period, starting from frame 0, for the mapping of SS/PBCH blocks toPRACH occasions is the smallest of {1, 2, 4} PRACH configuration periodsthat is larger than or equal to ┌N_(Tx) ^(SSB)/N_(PRACH period) ^(SSB)┐,where the UE obtains N_(Tx) ^(SSB) from higher layer parameterSSB-transmitted-SIB1 and N_(PRACH period) ^(SSB) s the number of SS/PBCHblocks that can be mapped to one PRACH configuration period.

If a random access procedure is initiated by a PDCCH order, the UEshall, if requested by higher layers, transmit a PRACH in the firstavailable PRACH occasion for which a time between the last symbol of thePDCCH order reception and the first symbol of the PRACH transmission islarger than or equal to N_(T,2)+Δ_(BWPSwitching)+Δ_(Delay) msec whereN_(T,2) is a time duration of N₂ symbols corresponding to a PUSCHpreparation time for PUSCH processing capability 1, Δ_(BWPSwitching) ispre-defined, and Δ_(Delay)>0.

In response to a PRACH transmission, a UE attempts to detect a PDCCHwith a corresponding RA-RNTI during a window controlled by higherlayers. The window starts at the first symbol of the earliest controlresource set the UE is configured for Type1-PDCCH common search spacethat is at least ┌(Δ·N_(slot) ^(subframe,μ)·N_(symb) ^(slot))/T_(sf)┐symbols after the last symbol of the preamble sequence transmission.

The length of the window in number of slots, based on the subcarrierspacing for Type0-PDCCH common search space is provided by higher layerparameter rar-WindowLength.

If a UE detects the PDCCH with the corresponding RA-RNTI and acorresponding PDSCH that includes a DL-SCH transport block within thewindow, the UE passes the transport block to higher layers. The higherlayers parse the transport block for a random access preamble identity(RAPID) associated with the PRACH transmission. If the higher layersidentify the RAPID in RAR message(s) of the DL-SCH transport block, thehigher layers indicate an uplink grant to the physical layer. This isreferred to as random access response (RAR) UL grant in the physicallayer. If the higher layers do not identify the RAPID associated withthe PRACH transmission, the higher layers can indicate to the physicallayer to transmit a PRACH. A minimum time between the last symbol of thePDSCH reception and the first symbol of the PRACH transmission is equalto N_(T,1)+Δ_(new)+0.5 msec where N_(T,1) is a time duration of N₁symbols corresponding to a PDSCH reception time for PDSCH processingcapability 1 when additional PDSCH DM-RS is configured and Δ_(new)≥0.

A UE shall receive the PDCCH with the corresponding RA-RNTI and thecorresponding PDSCH that includes the DL-SCH transport block with thesame DM-RS antenna port quasi co-location properties, as for a detectedSS/PBCH block or a received CSI-RS. If the UE attempts to detect thePDCCH with the corresponding RA-RNTI in response to a PRACH transmissioninitiated by a PDCCH order, the UE assumes that the PDCCH and the PDCCHorder have same DM-RS antenna port quasi co-location properties.

A RAR UL grant schedules a PUSCH transmission from the UE (Msg3 PUSCH).The contents of the RAR UL grant, starting with the MSB and ending withthe LSB, are given in Table 14. Table 14 shows random access responsegrant content field size.

TABLE 14 RAR grant field Number of bits Frequency hopping flag 1 Msg3PUSCH frequency resource 12 allocation Msg3 PUSCH time resource 4allocation MCS 4 TPC command for Msg3 PUSCH 3 CSI request 1 Reservedbits 3

The Msg3 PUSCH frequency resource allocation is for uplink resourceallocation type 1. In case of frequency hopping, based on the indicationof the frequency hopping flag field, the first one or two bits,N_(UL,hop) bits, of the Msg3 PUSCH frequency resource allocation fieldare used as hopping information bits as described in following [Table16].

The MCS is determined from the first sixteen indices of the applicableMCS index table for PUSCH.

The TPC command δ_(msg2,b,f,c) is used for setting the power of the Msg3PUSCH, and is interpreted according to Table 15. Table 15 shows TPCcommand δ_(msg2,b,f,c) for Msg3 PUSCH.

TABLE 15 TPC Command Value (in dB) 0 −6 1 −4 2 −2 3 0 4 2 5 4 6 6 7 8

In non-contention based random access procedure, the CSI request fieldis interpreted to determine whether an aperiodic CSI report is includedin the corresponding PUSCH transmission. In contention based randomaccess procedure, the CSI request field is reserved.

Unless a UE is configured a subcarrier spacing, the UE receivessubsequent PDSCH using same subcarrier spacing as for the PDSCHreception providing the RAR message.

If a UE does not detect the PDCCH with a corresponding RA-RNTI and acorresponding DL-SCH transport block within the window, the UE performsthe procedure for random access response reception failure.

For example, the UE may perform power ramping for retransmission of theRandom Access Preamble based on a power ramping counter. However, thepower ramping counter remains unchanged if a UE conducts beam switchingin the PRACH retransmissions as shown in FIG. 24 below.

In FIG. 24 , the UE may increase the power ramping counter by 1, whenthe UE retransmit the random access preamble for the same beam. However,when the beam had been changed, the power ramping counter remainsunchanged.

Regarding Msg3 PUSCH transmission, higher layer parameter msg3-tpindicates to a UE whether or not the UE shall apply transform precoding,for an Msg3 PUSCH transmission. If the UE applies transform precoding toan Msg3 PUSCH transmission with frequency hopping, the frequency offsetfor the second hop is given in Table 16. Table 16 shows frequency offsetfor second hop for Msg3 PUSCH transmission with frequency hopping.

TABLE 16 Number of PRBs Value of in N _(UL,hop) initial active HoppingFrequency offset UL BWP Bits for 2^(nd) hop N_(BWP) ^(size) < 50 0N_(BWP) ^(size)/2 1 N_(BWP) ^(size)/4 N_(BWP) ^(size) ≥ 50 00 N_(BWP)^(size)/2 01 N_(BWP) ^(size)/4 10 −N_(BWP) ^(size)/4 11 Reserved

The subcarrier spacing for Msg3 PUSCH transmission is provided by higherlayer parameter msg3-scs. A UE shall transmit PRACH and Msg3 PUSCH on asame uplink carrier of the same serving cell. An UL BWP for Msg3 PUSCHtransmission is indicated by SystemInformationBlockType1.

A minimum time between the last symbol of a PDSCH reception conveying aRAR and the first symbol of a corresponding Msg3 PUSCH transmissionscheduled by the RAR in the PDSCH for a UE when the PDSCH and the PUSCHhave a same subcarrier spacing is equal toN_(T,1)+N_(T,2)+N_(TA,max)+0.5 msec. N_(T,1) is a time duration of N₁symbols corresponding to a PDSCH reception time for PDSCH processingcapability 1 when additional PDSCH DM-RS is configured, N_(T,2) is atime duration of N² symbols corresponding to a PUSCH preparation timefor PUSCH processing capability 1, and N_(TA,max) is the maximum timingadjustment value that can be provided by the TA command field in theRAR. In response to an Msg3 PUSCH transmission when a UE has not beenprovided with a C-RNTI, the UE attempts to detect a PDCCH with acorresponding TC-RNTI scheduling a PDSCH that includes a UE contentionresolution identity. In response to the PDSCH reception with the UEcontention resolution identity, the UE transmits HARQ-ACK information ina PUCCH. A minimum time between the last symbol of the PDSCH receptionand the first symbol of the corresponding HARQ-ACK transmission is equalto N_(T,1)+0.5 msec. N_(T,1) is a time duration of N₁ symbolscorresponding to a PDSCH reception time for PDSCH processing capability1 when additional PDSCH DM-RS is configured.

Channel Coding Scheme

Channel coding schemes for one embodiment of the present inventionmainly includes: (1) LDPC (Low Density Parity Check) coding scheme fordata, and (2) Polar coding scheme for control information. Other codingschemes, such as repetition coding/simplex coding/Reed-Muller coding

Specifically, the network/UE may perform LDPC coding for PDSCH/PUSCHwith two base graph (BG) support. BG1 is for mother code rate 1/3, andBG2 is for mother code rate 1/5.

For the coding of control information, repetition coding/simplexcoding/Reed-Muller coding can be supported. Polar coding scheme can beused for the case when the control information has a length longer than11 bits. For DL, mother code size can be 512 and for UL, mother codesize can be 1024. Table 17 summarizes coding schemes for uplink controlinformation.

TABLE 17 Uplink Control Information size including CRC, if presentChannel code 1 Repetition code 2 Simplex code 3-11 Reed Muller code >11Polar code

As stated above, polar coding scheme can be used for PBCH. This codingscheme may be the same as in PDCCH.

LDPC coding structures are explained in detail.

LDPC code is a (n, k) linear block code defined as a null-space of a(n-k) x n spars parity check matrix H.

$\begin{matrix}{{{Hx}^{T} = 0}{{Hx}^{T} = {{\begin{bmatrix}1 & 1 & 1 & 0 & 0 \\1 & 0 & 0 & 1 & 1 \\1 & 1 & 0 & 0 & 0 \\0 & 1 & 1 & 1 & 0\end{bmatrix}\begin{bmatrix}x_{1} \\x_{2} \\x_{3} \\x_{4} \\x_{5}\end{bmatrix}} = \begin{bmatrix}0 \\0 \\0 \\0\end{bmatrix}}}} & \lbrack {{Equation}\mspace{14mu} 4} \rbrack\end{matrix}$

The parity-check matrix is represented by a protograph as in thefollowing FIG. 25 .

In one embodiment of the present invention, quasi-cyclic (QC) LDPC codeis used. In this embodiment, parity check matrix is am x n array of Z×Zcirculant permutation matrices. By using this QC LDPC, the complexity isreduced and highly parallelizable encoding and decoding can be acquired.

FIG. 26 shows an example of parity check matrix based on 4×4 circulantpermutation matrix.

In FIG. 26 , H is expressed by shift value (circulant matrix) and 0(=zero matrix) instead of Pi.

FIG. 27 shows encoder structure for polar code. Specifically, FIG. 27(a)shows the base module for polar code, and FIG. 27(b) shows the basematrix.

Polar code is known in the art as a code which can acquire channelcapacity in binary-input discrete memoryless channel (B-DMC). That is,channel capacity can be acquired when the size N of the code block isincreased unto infinite. The encoder of the Polar code performs channelcombining and channel splitting as shown in FIG. 28 .

UE States and State Transitions

FIG. 29 illustrates an UE RRC state machine and state transitions. A UEhas only one RRC state at one time.

FIG. 30 illustrates an UE state machine and state transitions as well asthe mobility procedures supported between NR/NGC and E-UTRAN/EPC.

The RRC state indicates whether an RRC layer of the UE is logicallyconnected to an RRC layer of an NG RAN.

The UE is either in RRC (radio resource control) CONNECTED state or inRRC_INACTIVE state when an RRC connection has been established. If thisis not the case, i.e. no RRC connection is established, the UE is inRRC_IDLE state.

When in the RRC connected state or RRC INACTIVE state, the UE has an RRCconnection and thus the NG RAN can recognize a presence of the UE in acell unit. Accordingly, the UE can be effectively controlled. On theother hand, when in the RRC idle state, the UE cannot be recognized bythe NG RAN, and is managed by a core network in a tracking area unitwhich is a unit of a wider area than a cell. That is, regarding the UEin the RRC idle state, only a presence or absence of the UE isrecognized in a wide area unit. To get a typical mobile communicationservice such as voice or data, a transition to the RRC connected stateis necessary.

When a user initially powers on the UE, the UE first searches for aproper cell and thereafter stays in the RRC idle state in the cell. Onlywhen there is a need to establish an RRC connection, the UE staying inthe RRC idle state establishes the RRC connection with the NG RANthrough an RRC connection procedure and then transitions to the RRCconnected state or RRC_INACTIVE state. Examples of a case where the UEin the RRC idle state needs to establish the RRC connection are various,such as a case where uplink data transmission is necessary due totelephony attempt of the user or the like or a case where a responsemessage is transmitted in response to a paging message received from theNG RAN.

The RRC IDLE state and the RRC INACTIVE state have the followingcharacteristics.

(1) RRC_IDLE:

-   -   A UE specific DRX (discontinuous reception) may be configured by        upper layers;    -   UE controlled mobility based on network configuration;    -   The UE:    -   Monitors a Paging channel;    -   Performs neighbouring cell measurements and cell (re-)selection;    -   Acquires system information.

(2) RRC_INACTIVE:

-   -   A UE specific DRX may be configured by upper layers or by RRC        layer;    -   UE controlled mobility based on network configuration;    -   The UE stores the AS (Access Stratum) context;    -   The UE:    -   Monitors a Paging channel;    -   Performs neighbouring cell measurements and cell (re-)selection;    -   Performs RAN-based notification area updates when moving outside        the RAN-based notification area;    -   Acquires system information.

(3) RRC_CONNECTED:

-   -   The UE stores the AS context;    -   Transfer of unicast data to/from UE;    -   At lower layers, the UE may be configured with a UE specific        DRX;    -   For UEs supporting CA, use of one or more SCells, aggregated        with the SpCell, for increased bandwidth;    -   For UEs supporting DC, use of one SCG, aggregated with the MCG,        for increased bandwidth;    -   Network controlled mobility within NR and to/from E-UTRAN;    -   The UE:    -   Monitors a Paging channel;    -   Monitors control channels associated with the shared data        channel to determine if data is scheduled for it;    -   Provides channel quality and feedback information;    -   Performs neighbouring cell measurements and measurement        reporting;    -   Acquires system information.

RRC Idle State and RRC Inactive State

The procedure of the UE related to the RRC_IDLE state and RRC_INACTIVEstate can be summarized as Table 18.

TABLE 18 UE procedure 1^(st) Step a public land mobile network (PLMN)selection when a UE is switched on 2^(nd) Step cell (re)selection forsearching a suitable cell 3^(rd) Step tune to its control channel(camping on the cell) 4^(th) Step Location registration and a RAN-basedNotification Area (RNA) update

The PLMN selection, cell reselection procedures, and locationregistration are common for both RRC_IDLE state and RRC_INACTIVE state.

When a UE is switched on, the PLMN is selected by NAS (Non-AccessStratum). For the selected PLMN, associated RAT (Radio AccessTechnology)(s) may be set. The NAS shall provide a list of equivalentPLMNs, if available, that the AS shall use for cell selection and cellreselection.

With the cell selection, the UE searches for a suitable cell of theselected PLMN and chooses that cell to provide available services,further the UE shall tune to its control channel. This choosing is knownas “camping on the cell”.

The following three levels of services are provided while a UE is inRRC_IDLE state:

-   -   Limited service (emergency calls, ETWS and CMAS on an acceptable        cell);    -   Normal service (for public use on a suitable cell);    -   Operator service (for operators only on a reserved cell).

The following two levels of services are provided while a UE is inRRC_INACTIVE state:

-   -   Normal service (for public use on a suitable cell);    -   Operator service (for operators only on a reserved cell).

The UE shall, if necessary, then register its presence, by means of aNAS registration procedure, in the tracking area of the chosen cell and,as outcome of a successful Location Registration, the selected PLMNbecomes the registered PLMN.

If the UE finds a more suitable cell, according to the cell reselectioncriteria, it reselects onto that cell and camps on it. If the new celldoes not belong to at least one tracking area to which the UE isregistered, location registration is performed. In RRC_INACTIVE state,if the new cell does not belong to the configured RNA, a RNA updateprocedure is performed.

If necessary, the UE shall search for higher priority PLMNs at regulartime intervals and search for a suitable cell if another PLMN has beenselected by NAS.

If the UE loses coverage of the registered PLMN, either a new PLMN isselected automatically (automatic mode), or an indication of which PLMNsare available is given to the user, so that a manual selection can bemade (manual mode).

Registration is not performed by UEs only capable of services that needno registration.

The purpose of camping on a cell in RRC_IDLE state and RRC_INACTIVEstate is fourfold:

-   -   a) It enables the UE to receive system information from the        PLMN.    -   b) When registered and if the UE wishes to establish an RRC        connection, it can do this by initially accessing the network on        the control channel of the cell on which it is camped.    -   c) If the PLMN receives a call for the registered UE, it knows        (in most cases) the set of tracking areas (in RRC_IDLE state) or        RNAs (in RRC_INACTIVE state) in which the UE is camped. It can        then send a “paging” message for the UE on the control channels        of all the cells in the corresponding set of areas. The UE will        then receive the paging message and can respond.

The three processes distinguished from the RRC_IDLE state and theRRC_INACTIVE state will now be described in more detail.

First, the PLMN selection procedure will be described.

In the UE, the AS shall report available PLMNs to the NAS on requestfrom the NAS or autonomously.

During PLMN selection, based on the list of PLMN identities in priorityorder, the particular PLMN may be selected either automatically ormanually. Each PLMN in the list of PLMN identities is identified by a‘PLMN identity’. In the system information on the broadcast channel, theUE can receive one or multiple ‘PLMN identity’ in a given cell. Theresult of the PLMN selection performed by NAS is an identifier of theselected PLMN.

The UE shall scan all RF channels in the NR bands according to itscapabilities to find available PLMNs. On each carrier, the UE shallsearch for the strongest cell and read its system information, in orderto find out which PLMN(s) the cell belongs to. If the UE can read one orseveral PLMN identities in the strongest cell, each found PLMN shall bereported to the NAS as a high quality PLMN (but without the RSRP value),provided that the following high quality criterion is fulfilled:

For a NR cell, the measured RSRP value shall be greater than or equal to−110 dBm.

Found PLMNs that do not satisfy the high quality criterion but for whichthe UE has been able to read the PLMN identities are reported to the NAStogether with the RSRP value. The quality measure reported by the UE toNAS shall be the same for each PLMN found in one cell.

The search for PLMNs may be stopped on request of the NAS. The UE mayoptimize PLMN search by using stored information e.g. carrierfrequencies and optionally also information on cell parameters frompreviously received measurement control information elements.

Once the UE has selected a PLMN, the cell selection procedure shall beperformed in order to select a suitable cell of that PLMN to camp on.

Next, cell selection and cell reselection will be described

UE shall perform measurements for cell selection and reselectionpurposes.

The NAS can control the RAT(s) in which the cell selection should beperformed, for instance by indicating RAT(s) associated with theselected PLMN, and by maintaining a list of forbidden registrationarea(s) and a list of equivalent PLMNs. The UE shall select a suitablecell based on RRC_IDLE state measurements and cell selection criteria.

In order to expedite the cell selection process, stored information forseveral RATs may be available in the UE.

When camped on a cell, the UE shall regularly search for a better cellaccording to the cell reselection criteria. If a better cell is found,that cell is selected. The change of cell may imply a change of RAT. TheNAS is informed if the cell selection and reselection result in changesin the received system information relevant for NAS.

For normal service, the UE shall camp on a suitable cell, tune to thatcell's control channel(s) so that the UE can:

-   -   Receive system information from the PLMN; and    -   receive registration area information from the PLMN, e.g.,        tracking area information; and    -   receive other AS and NAS Information; and    -   if registered:    -   receive paging and notification messages from the PLMN; and    -   initiate transfer to Connected mode.

For cell selection, measurement quantity of a cell is up to UEimplementation.

For cell reselection in multi-beam operations, using a maximum number ofbeams to be considered and a threshold which are provided inSystemInformationBlockTypeX, measurement quantity of a cell is derivedamongst the beams corresponding to the same cell based on SS/PBCH blockas follows:

-   -   if the highest beam measurement quantity value is below the        threshold:    -   derive a cell measurement quantity as the highest beam        measurement quantity value;    -   else:    -   derive a cell measurement quantity as the linear average of the        power values of up to the maximum number of highest beam        measurement quantity values above the threshold.

Cell selection is performed by one of the following two procedures:

-   -   a) Initial cell selection (no prior knowledge of which RF        channels are NR carriers);    -   1. The UE shall scan all RF channels in the NR bands according        to its capabilities to find a suitable cell.    -   2. On each carrier frequency, the UE need only search for the        strongest cell.    -   3. Once a suitable cell is found this cell shall be selected.    -   b) Cell selection by leveraging stored information.    -   1. This procedure requires stored information of carrier        frequencies and optionally also information on cell parameters,        from previously received measurement control information        elements or from previously detected cells.    -   2. Once the UE has found a suitable cell the UE shall select it.    -   3. If no suitable cell is found the Initial Cell Selection        procedure shall be started.

Next, the procedure of cell reservations and access restrictions will bedescribed

There are two mechanisms which allow an operator to impose cellreservations or access restrictions. The first mechanism uses indicationof cell status and special reservations for control of cell selectionand reselection procedures. The second mechanism, referred to as UnifiedAccess Control, shall allow preventing selected access categories oraccess identities from sending initial access messages for load controlreasons.

Cell status and cell reservations are indicated in theMasterinformationBlock or SystemInformationBlockType1 (SIB1) message bymeans of three fields:

-   -   cellBarred (IE type: “barred” or “not barred”)

Indicated in MasterinformationBlock message. In case of multiple PLMNsindicated in SIB1, this field is common for all PLMNs

-   -   cellReservedForOperatorUse (IE type: “reserved” or “not        reserved”)

Indicated in SystemInformationBlockType1 message. In case of multiplePLMNs indicated in SIB1, this field is specified per PLMN.

-   -   cellReservedForOtherUse (IE type: “reserved” or “not reserved”)

Indicated in SystemInformationBlockType1 message. In case of multiplePLMNs indicated in SIB1, this field is common for all PLMNs.

When cell status is indicated as “not barred” and “not reserved” foroperator use and “not reserved” for other use,

-   -   All UEs shall treat this cell as candidate during the cell        selection and cell reselection procedures.

When cell status is indicated as “reserved” for other use,

-   -   The UE shall treat this cell as if cell status is “barred”.

When cell status is indicated as “not barred” and “reserved” foroperator use for any PLMN and “not reserved” for other use,

-   -   UEs assigned to Access Identity 11 or 15 operating in their        HPLMN/EHPLMN shall treat this cell as candidate during the cell        selection and reselection procedures if the field        cellReservedForOperatorUse for that PLMN set to “reserved”.    -   UEs assigned to an Access Identity in the range of 12 to 14        shall behave as if the cell status is “barred” in case the cell        is “reserved for operator use” for the registered PLMN or the        selected PLMN.

When cell status “barred” is indicated or to be treated as if the cellstatus is “barred”,

-   -   The UE is not permitted to select/reselect this cell, not even        for emergency calls.    -   The UE shall select another cell according to the following        rule:    -   If the cell is to be treated as if the cell status is “barred”        due to being unable to acquire the MasterinformationBlock or the        SystemInformationBlockType1:    -   the UE may exclude the barred cell as a candidate for cell        selection/reselection for up to 300 seconds.    -   the UE may select another cell on the same frequency if the        selection criteria are fulfilled.    -   else    -   If the field intraFreqReselection in MasterinformationBlock        message is set to “allowed”, the UE may select another cell on        the same frequency if re-selection criteria are fulfilled.    -   The UE shall exclude the barred cell as a candidate for cell        selection/reselection for 300 seconds.    -   If the field intraFreqReselection in MasterinformationBlock        message is set to “not allowed” the UE shall not re-select a        cell on the same frequency as the barred cell;    -   The UE shall exclude the barred cell and the cells on the same        frequency as a candidate for cell selection/reselection for 300        seconds.

The cell selection of another cell may also include a change of RAT.

The information on cell access restrictions associated with AccessCategories and Identities is broadcasted as system information.

The UE shall ignore Access Category and Identity related cell accessrestrictions for cell reselection. A change of the indicated accessrestriction shall not trigger cell reselection by the UE.

The UE shall consider Access Category and Identity related cell accessrestrictions for NAS initiated access attempts and RNAU.

Next, the procedure of tracking area registration and of RAN Arearegistration will be described.

In the UE, the AS shall report tracking area information to the NAS.

If the UE reads more than one PLMN identity in the current cell, the UEshall report the found PLMN identities that make the cell suitable inthe tracking area information to NAS.

The UE sends a RAN-based notification area update (RNAU) periodically orwhen the UE selects a cell that does not belong to the configured RNA.

Next, Mobility in RRC IDLE and RRC INACTIVE will be described in moredetail.

The principles of PLMN selection in NR are based on the 3GPP PLMNselection principles. Cell selection is required on transition fromRM-DEREGISTERED to RM-REGISTERED, from CM-IDLE to CM-CONNECTED and fromCM-CONNECTED to CM-IDLE and is based on the following principles:

-   -   The UE NAS layer identifies a selected PLMN and equivalent        PLMNs;    -   The UE searches the NR frequency bands and for each carrier        frequency identifies the strongest cell. It reads cell system        information broadcast to identify its PLMN(s):    -   The UE may search each carrier in turn (“initial cell        selection”) or make use of stored information to shorten the        search (“stored information cell selection”).    -   The UE seeks to identify a suitable cell; if it is not able to        identify a suitable cell it seeks to identify an acceptable        cell. When a suitable cell is found or if only an acceptable        cell is found it camps on that cell and commence the cell        reselection procedure:    -   A suitable cell is one for which the measured cell attributes        satisfy the cell selection criteria; the cell PLMN is the        selected PLMN, registered or an equivalent PLMN; the cell is not        barred or reserved and the cell is not part of a tracking area        which is in the list of “forbidden tracking areas for roaming”;    -   An acceptable cell is one for which the measured cell attributes        satisfy the cell selection criteria and the cell is not barred.

Transition to RRC_IDLE:

On transition from RRC_CONNECTED to RRC_IDLE, a UE should camp on thelast cell for which it was in RRC_CONNECTED or a cell/any cell of set ofcells or frequency be assigned by RRC in the state transition message.

Recovery from Out of Coverage:

The UE should attempt to find a suitable cell in the manner describedfor stored information or initial cell selection above. If no suitablecell is found on any frequency or RAT, the UE should attempt to find anacceptable cell.

In multi-beam operations, the cell quality is derived amongst the beamscorresponding to the same cell.

A UE in RRC_IDLE performs cell reselection. The principles of theprocedure are the following:

-   -   The UE makes measurements of attributes of the serving and        neighbour cells to enable the reselection process:    -   For the search and measurement of inter-frequency neighbouring        cells, only the carrier frequencies need to be indicated.    -   Cell reselection identifies the cell that the UE should camp on.        It is based on cell reselection criteria which involves        measurements of the serving and neighbour cells:    -   Intra-frequency reselection is based on ranking of cells;    -   Inter-frequency reselection is based on absolute priorities        where a UE tries to camp on the highest priority frequency        available;    -   An NCL can be provided by the serving cell to handle specific        cases for intra- and inter-frequency neighbouring cells;    -   Black lists can be provided to prevent the UE from reselecting        to specific intra- and inter-frequency neighbouring cells;    -   Cell reselection can be speed dependent;    -   Service specific prioritization.

In multi-beam operations, the cell quality is derived amongst the beamscorresponding to the same cell.

RRC_INACTIVE is a state where a UE remains in CM-CONNECTED and can movewithin an area configured by NG-RAN (the RNA) without notifying NG-RAN.In RRC_INACTIVE, the last serving gNB node keeps the UE context and theUE-associated NG connection with the serving AMF and UPF.

If the last serving gNB receives DL data from the UPF or DL signallingfrom the AMF while the UE is in RRC_INACTIVE, it pages in the cellscorresponding to the RNA and may send XnAP RAN Paging to neighbourgNB(s) if the RNA includes cells of neighbour gNB(s).

The AMF provides to the NG-RAN node the RRC Inactive AssistantInformation to assist the NG-RAN node's decision whether the UE can besent to RRC_INACTIVE. The RRC Inactive Assistant Information includesthe registration area configured for the UE, the UE specific DRX,Periodic Registration Update timer, an indication if the UE isconfigured with Mobile Initiated Connection Only (MICO) mode by the AMF,and UE Identity Index value. The UE registration area is taken intoaccount by the NG-RAN node when configuring the RAN-based notificationarea. The UE specific DRX and UE Identity Index value are used by theNG-RAN node for RAN paging. The Periodic Registration Update timer istaken into account by the NG-RAN node to configure Periodic RANNotification Area Update timer.

At transition to RRC_INACTIVE the NG-RAN node may configure the UE witha periodic RNA Update timer value.

If the UE accesses a gNB other than the last serving gNB, the receivinggNB triggers the XnAP Retrieve UE Context procedure to get the UEcontext from the last serving gNB and may also trigger a Data Forwardingprocedure including tunnel information for potential recovery of datafrom the last serving gNB. Upon successful context retrieval, thereceiving gNB becomes the serving gNB and it further triggers the NGAPPath Switch Request procedure. After the path switch procedure, theserving gNB triggers release of the UE context at the last serving gNBby means of the XnAP UE Context Release procedure.

If the UE accesses a gNB other than the last serving gNB and thereceiving gNB does not find a valid UE Context, gNB performsestablishment of a new RRC connection instead of resumption of theprevious RRC connection.

A UE in the RRC_INACTIVE state is required to initiate RNA updateprocedure when it moves out of the configured RNA. When receiving RNAupdate request from the UE, the receiving gNB may decide to send the UEback to RRC_INACTIVE state, move the UE into RRC_CONNECTED state, orsend the UE to RRC_IDLE.

A UE in RRC_INACTIVE performs cell reselection. The principles of theprocedure are as for the RRC_IDLE state.

DRX (Discontinuous Reception)

The procedure of the UE related to the DRX can be summarized as Table19.

TABLE 19 Type of signals UE procedure 1^(st) Step RRC signalling (MAC-Receive DRX configuration CellGroupConfig) information 2^(nd) Step MACCE ((Long) DRX Receive DRX command command MAC CE) 3^(rd) Step — Monitora PDCCH during an on-duration of a DRX cycle

FIG. 31 illustrates a DRX cycle.

The UE uses Discontinuous Reception (DRX) in RRC_IDLE and RRC_INACTIVEstate in order to reduce power consumption.

When the DRX is configured, the UE performs a DRX operation according toDRX configuration information.

An UE operating as the DRX repeatedly turns its reception performance ONand OFF.

For example, when the DRX is configured, the UE tries to receive thePDCCH, which is a downlink channel only in a predetermined timeinterval, and does not attempt to receive the PDCCH in the remainingtime period. At this time, a time period during which the UE shouldattempt to receive the PDCCH is referred to as an On-duration, and thison-duration is defined once per DRX cycle.

The UE can receive DRX configuration information from a gNB through aRRC signaling and operate as the DRX through a reception of the (Long)DRX command MAC CE.

The DRX configuration information may be included in theMAC-CellGroupConfig.

The IE MAC-CellGroupConfig is used to configure MAC parameters for acell group, including DRX.

Table 20 and Table 21 show an example of the IE MAC-CellGroupConfig.

TABLE 20 -- ASN1START -- TAG-MAC-CELL-GROUP-CONFIG-STARTMAC-CellGroupConfig ::=     SEQUENCE {  drx-Config           SetupRelease { DRX-Config }  schedulingRequestConfig    SchedulingRequestConfig  bsr-Config            BSR-Config tag-Config            TAG-Config  phr-Config            SetupRelease {PHR-Config }  skipUplinkTxDynamic        BOOLEAN,  cs-RNTI            SetupRelease { RNTI-Value } } DRX-Config ::=        SEQUENCE {  drx-onDurationTimer       CHOICE {                 subMilliSeconds INTEGER (1 . . . 31),                 milliSeconds ENUMERATED {                 ms1, ms2,ms3, ms4, ms5, ms6, ms8, ms10,                 ms20, ms30, ms40, ms50,ms60, ms80, ms100,                 ms200, ms300, ms400, ms500, ms600,ms800,                 ms1000, ms1200, ms1600, spare9, spare8, spare7,                spare6, spare5, spare4, spare3, spare2, spare1}                   },  drx-InactivityTimer        ENUMERATED {                ms0, ms1, ms2, ms3, ms4, ms5, ms6, ms8, ms10,                ms20, ms30, ms40, ms50, ms60, ms80, ms100,                ms200, ms300, ms500, ms750, ms1280, ms1920,                ms2560, spare9, spare8, spare7, spare6, spare5,                spare4, spare3, spare2, spare1},  drx-HARQ-RTT-TimerDL    INTEGER (0 . . . 56),  drx-HARQ-RTT-TimerUL     INTEGER (0 . . .56),  drx-RetransmissionTimerDL     ENUMERATED {                 sl0,sl1, sl2, sl4, sl6, sl8, sl16, sl24, sl33, sl40,                 sl64,sl80, sl96, sl112, sl128, sl160, sl320,                 spare15,spare14, spare13, spare12, spare11,                 spare10, spare9,spare8, spare7, spare6, spare5,                 spare4, spare3, spare2,spare1},  drx-RetransmissionTimerUL    ENUMERATED {                 sl0,sl1, sl2, sl4, sl6, sl8, sl16, sl24, sl33, sl40,                 sl64,sl80, sl96, sl112, sl128, sl160, sl320,                 spare15,spare14, spare13, spare12, spare11,                 spare10, spare9,spare8, spare7, spare6, spare5,                 spare4, spare3, spare2,spare1 },  drx-LongCycleStartOffset CHOICE {   ms10              INTEGER(0 . . . 9),   ms20               INTEGER(0 . . . 19),   ms32              INTEGER(0 . . . 31),   ms40               INTEGER(0 . . .39),   ms60               INTEGER(0 . . . 59),   ms64              INTEGER(0 . . . 63),   ms70               INTEGER(0 . . . 69),   ms80              INTEGER(0 . . . 79),   ms128             INTEGER(0 . . .127),   ms160             INTEGER(0 . . . 159),  ms256             INTEGER(0 . . . 255),   ms320             INTEGER(0. . . 319),   ms512             INTEGER(0 . . . 511),  ms640             INTEGER(0 . . . 639),   ms1024             INTEGER(0 . . . 1023),   ms1280              INTEGER(0 . . . 1279),  ms2048              INTEGER(0 . . . 2047),   ms2560             INTEGER(0 . . . 2559),   ms5120              INTEGER(0 . . . 5119),  ms10240           INTEGER(0 . . . 10239)  },   shortDRX           SEQUENCE {    drx-ShortCycle         ENUMERATED {                   ms2, ms3, ms4, ms5, ms6, ms7, ms8,                   ms10, ms14, ms16, ms20, ms30, ms32,                    ms35, ms40, ms64,ms80, ms128, ms160,                    ms256, ms320, ms512, ms640,spare9,                    spare8, spare7, spare6, spare5, spare4,                   spare3, spare2, spare1 },   drx-ShortCycleTimer       INTEGER (1 . . . 16)  }   OPTIONAL,                       -- Need R  drx-SlotOffset          INTEGER (0 . .. 31) }

TABLE 21   MAC-CellGroupConfig field descriptions drx-Config Used toconfigure DRX. drx-HARQ-RTT-TimerDL Value in number of symbols.drx-HARQ-RTT-TimerUL Value in number of symbols. drx-InactivityTimerValue in multiple integers of 1 ms. ms0 corresponds to 0, ms1corresponds to 1 ms, ms2 corresponds to 2 ms, and so on. drx-onDurationTimer Value in multiples of 1/32 ms (subMilliSeconds) or in ms(milliSecond). For the latter, ms1 corresponds to 1 ms, ms2 correspondsto 2 ms, and so on. drx-LongCycleStart Offset drx-LongCycle in ms anddrx-StartOffset in multiples of 1 ms. drx-RetransmissionTimerDL Value innumber of slot lengths. sl1 corresponds to 1 slot, sl2 corresponds to 2slots, and so on. drx-RetransmissionTimerUL Value in number of slotlengths. sl1 corresponds to 1 slot, sl2 corresponds to 2 slots, and soon. drx-ShortCycle Value in ms. ms1 corresponds to 1 ms, ms2 correspondsto 2 ms, and so on. drx-ShortCycleTimer Value in multiples ofdrx-ShortCycle. A value of 1 corresponds to drx-ShortCycle, a value of 2corresponds to 2 * drx-ShortCycle and so on. drx-SlotOffset Value in1/32 ms. Value 0 corresponds to 0 ms, value 1 corresponds to 1/32 ms,value 2 corresponds to 2/32 ms, and so on.

The drx-onDurationTimer is the duration at the beginning of a DRX Cycle.

The drx-SlotOffset is the delay in slots before starting thedrx-onDurationTimer.

The drx-StartOffset is the subframe where the DRX Cycle starts.

The drx-Inactivity Timer is the duration after the PDCCH occasion inwhich a PDCCH indicates an initial UL or DL user data transmission forthe MAC entity.

The drx-RetransmissionTimerDL (per DL HARQ process) is the maximumduration until a DL retransmission is received.

The drx-RetransmissionTimerUL (per UL HARQ process) is the maximumduration until a grant for UL retransmission is received.

The drx-LongCycle is the Long DRX cycle.

The drx-ShortCycle (optional) is the Short DRX cycle.

The drx-ShortCycle Timer (optional) is the duration the UE shall followthe Short DRX Cycle.

The drx-HARQ-RTT-TimerDL (per DL HARQ process) is the minimum durationbefore a DL assignment for HARQ retransmission is expected by the MACentity.

The drx-HARQ-RTT-TimerUL (per UL HARQ process) is the minimum durationbefore a UL HARQ retransmission grant is expected by the MAC entity.

The DRX Command MAC CE or the Long DRX Command MAC CE is identified by aMAC PDU subheader with LCD. It has a fixed size of zero bits.

Table 22 shows an example of values of LCID for DL-SCH.

TABLE 22 Index LCID values 111011 Long DRX Command 111100 DRX Command

The PDCCH monitoring activity of the UE is governed by DRX and BA.

When DRX is configured, the UE does not have to continuously monitorPDCCH.

DRX is characterized by the following.

-   -   on-duration: duration that the UE waits for, after waking up, to        receive PDCCHs. If the UE successfully decodes a PDCCH, the UE        stays awake and starts the inactivity timer;    -   inactivity-timer: duration that the UE waits to successfully        decode a PDCCH, from the last successful decoding of a PDCCH,        failing which it can go back to sleep. The UE shall restart the        inactivity timer following a single successful decoding of a        PDCCH for a first transmission only (i.e. not for        retransmissions);    -   retransmission-timer: duration until a retransmission can be        expected;    -   cycle: specifies the periodic repetition of the on-duration        followed by a possible period of inactivity.

Next, the DRX described in the MAC layer will be described. The MACentity used below may be expressed as a UE or a MAC entity of an UE.

The MAC entity may be configured by RRC with a DRX functionality thatcontrols the UE's PDCCH monitoring activity for the MAC entity's C-RNTI,CS-RNTI, TPC-PUCCH-RNTI, TPC-PUSCH-RNTI, and TPC-SRS-RNTI. When usingDRX operation, the MAC entity shall also monitor PDCCH. When inRRC_CONNECTED, if DRX is configured, the MAC entity may monitor thePDCCH discontinuously using the DRX operation; otherwise the MAC entityshall monitor the PDCCH continuously.

RRC controls DRX operation by configuring parameters as table 3 andtable 4 (DRX configuration information).

When a DRX cycle is configured, the Active Time includes the time while:

-   -   drx-onDurationTimer or drx-InactivityTimer or        drx-RetransmissionTimerDL or drx-RetransmissionTimerUL or        ra-ContentionResolutionTimer is running; or    -   a Scheduling Request is sent on PUCCH and is pending; or    -   a PDCCH indicating a new transmission addressed to the C-RNTI of        the MAC entity has not been received after successful reception        of a Random Access Response for the Random Access Preamble not        selected by the MAC entity among the contention-based Random        Access Preamble.

When DRX is configured, the MAC entity shall perform an operation asTable. 23.

TABLE 23 1>  if a MAC PDU is transmitted in a configured uplink grant: 2>start the drx-HARQ-RTT-TimerUL for the corresponding HARQ    processimmediately after the first repetition of the corresponding    PUSCHtransmission;  2>stop the drx-RetransmissionTimerUL for thecorresponding HARQ    process. 1>  if a drx-HARQ-RTT-TimerDL expires: 2>if the data of the corresponding HARQ process was not successfully  decoded:   3>start the drx-RetransmissionTimerDL for the correspondingHARQ     process. 1>    if a drx-HARQ-RTT-TimerUL expires:  2>start thedrx-RetransmissionTimerUL for the corresponding HARQ   process. 1>   ifa DRX Command MAC CE or a Long DRX Command MAC CE is received:  2>stopdrx-onDurationTimer;  2>stop drx-InactivityTimer. 1>   ifdrx-InactivityTimer expires or a DRX Command MAC CE is received:  2>ifthe Short DRX cycle is configured:   3>start or restartdrx-ShortCycleTimer;   3>use the Short DRX Cycle.  2>else:   3>use theLong DRX cycle. 1>   if drx-ShortCycleTimer expires:  2>use the Long DRXcycle. 1>   if a Long DRX Command MAC CE is received:  2>stopdrx-ShortCycleTimer;  2>use the Long DRX cycle. 1>   if the Short DRXCycle is used, and [(SFN × 10) + subframe number] modulo(drx-ShortCycle) = (drx-StartOffset) modulo (drx-ShortCycle); or 1>   ifthe Long DRX Cycle is used, and [(SFN × 10) + subframe number] modulo(drx-LongCycle) = drx-StartOffset:  2>if drx-SlotOffset is configured:  3>start drx-onDurationTimer after drx-SlotOffset.  2>else:   3>startdrx-onDurationTimer. 1>   if the MAC entity is in Active Time: 2>monitor the PDCCH;  2>if the PDCCH indicates a DL transmission or ifa DL assignment has   been configured:   3>start thedrx-HARQ-RTT-TimerDL for the corresponding HARQ    process immediatelyafter the corresponding PUCCH transmission;   3>stop thedrx-RetransmissionTimerDL for the corresponding HARQ    process.  2>ifthe PDCCH indicates a UL transmission:   3>start thedrx-HARQ-RTT-TimerUL for the corresponding HARQ    process immediatelyafter the first repetition of the corresponding    PUSCH transmission;  3>stop the drx-RetransmissionTimerUL for the corresponding HARQ   process.  2>if the PDCCH indicates a new transmission (DL or UL):  3>start or restart drx-InactivityTimer. 1>   else (i.e. not part ofthe Active Time):  2>not transmit type-0-triggered SRS. 1>   if CQImasking (cqi-Mask) is setup by upper layers:  2>if drx-onDurationTimeris not running:   3>not report CSI on PUCCH. 1>   else:  2>if the MACentity is not in Active Time:   3>not report CSI on PUCCH.

Regardless of whether the MAC entity is monitoring PDCCH or not, the MACentity transmits HARQ feedback and type-1-triggered SRS when such isexpected.

The MAC entity needs not to monitor the PDCCH if it is not a completePDCCH occasion (e.g., the Active Time starts or expires in the middle ofa PDCCH occasion).

Next, a DRX for paging will be described.

The UE may use Discontinuous Reception (DRX) in RRC_IDLE andRRC_INACTIVE state in order to reduce power consumption. The UE monitorsone paging occasion (PO) per DRX cycle and one PO can consist ofmultiple time slots (e.g., subframe or OFDM symbol) where paging DCI canbe sent. In multi-beam operations, the length of one PO is one period ofbeam sweeping and the UE can assume that the same paging message isrepeated in all beams of the sweeping pattern. The paging message issame for both RAN initiated paging and CN initiated paging.

One Paging Frame (PF) is one Radio Frame, which may contain one ormultiple Paging Occasion(s).

The UE initiates RRC Connection Resume procedure upon receiving RANpaging. If the UE receives a CN initiated paging in RRC_INACTIVE state,the UE moves to RRC_IDLE and informs NAS.

Meanwhile, UEs supporting V2X communication perform communication usingfrequency resources available for each UE in a resource pool usable forsidelink communication. In this case, as the number of neighboring UEsincreases and the number of UEs performing transmission using differentfrequencies at the same time increases, there is a high probability thatinterference between UEs will increase due to in-band emission (IBE),etc. FIG. 32 illustrates an example of an IBE mask. Generally,relatively high IBE interference occurs at a part adjacent to afrequency resource on which a UE transmits a desired signal andrelatively low IBE interference appears at a part (indicated by obliquelines) distant from the frequency resource.

Such interference caused by IBE may equally occur with respect to both acontrol channel and a data channel. However, in particular, when thecontrol channel includes various attributes of the data channel, forexample, priority information of data, the position of a resource usedfor data transmission, a modulation and coding scheme, and/or HARQrelated information, or when the control channel includes feedbackinformation necessary for future data transmission, for example,HARQ-ACK indicating whether previous data has been successfully receivedor channel status information indicating a current channel status, it isnecessary to protect the control channel from such interference. Inparticular, since (1) some UEs may need to decode only a control signalfor the purpose of sensing, (2) HARQ combining may be performed evenwhen a data signal fails to be decoded or received after the controlsignal is decoded, or (3) data transmission a several number of timesmay be optimized later based on feedback information, it is necessary toprotect the control channel from interference. Accordingly, an influenceof interference on the control channel needs to be additionally reduced.Hereinbelow, a method will be described capable of raising decodingperformance of the control signal by efficiently configuring thelocation of the control channel in a resource pool in an environment inwhich interference between V2X UEs occurs.

EMBODIMENTS

A UE according to embodiment(s) may determine PSCCH candidate resourcesassociated with PSSCH candidate resources (S3301 of FIG. 33 ) andtransmit a PSCCH using at least partial resources of the PSCCH candidateresources (S3302).

Here, the at least partial resources may include Z successive resourceblocks (RBs) and include a center frequency of the PSCCH candidateresources on the frequency axis. Thereby, only some resources located ata middle part among PSCCH candidate resources linked/associated withresources occupied by a PSSCH of the UE may be configured as candidateresources on which the PSCCH is actually transmittable in order toreduce an influence caused by IBE. In addition, Z may be constantregardless of change in the size of the associated PSSCH candidateresources. That is, the UE may select a region in which the PSCCH istransmitted regardless of the size of frequency resources used for PSSCHtransmission. Among the PSCCH candidate resources, a resource regionwhich does not correspond to the PSCCH transmission resources maycorrespond to a guard band of the PSCCH, and the PSCCH candidateresources associated with the PSSCH candidate resources may be equal tothe PSSCH candidate resources in the size of a frequency resourceregion.

That is, as illustrated in FIG. 34 , among PSCCH candidate resources(PSSCH candidate resources of FIG. 34 ) linked/associated with frequencyresources occupied by the PSSCH (PSSCH candidate resources), the Z RBsmay be determined as actual PSCCH candidate resources, and the PSCCH maybe transmitted using all or some of the Z RBs. In FIG. 35 , when afrequency resource region occupied by the UE is divided into threesub-channels, a PSCCH region is selected only within one sub-channelpositioned at a middle part of the 3 sub-channels. In this case, thePSCCH is not transmitted in a region other than a region in which thePSCCH is actually transmitted among the PSCCH candidate resources andthe region in which the PSCCH is not transmitted serves as a guard bandfor the transmitted PSCCH. In FIG. 35 , (b) illustrates that a region inwhich the PSCCH is transmitted is uniform (only a region of onesub-channel is selected) even when the size of frequency resources usedfor PSSCH transmission is reduced (to one sub-channel). In this case, itmay be noted that there is no guard band for the PSCCH. In such aconfiguration, since the size of PSCCH candidate resources may beuniformly maintained even when the size of PSSCH transmission resourcesbecomes different, the number of operations of attempting to detect manyPSCCHs in a wide range of PSCCH candidate resource positions at areception side may be reduced.

The Z RBs selected from among the PSCCH candidate resources may use allcandidate resources or may use some thereof randomly or according to apredetermined rule. Additionally, the reason why the PSCCH istransmitted by selecting some resources is to satisfy the necessity ofsucceeding in receiving even the above-described PSCCH since there is apossibility that the PSCCH transmission resources may be different evenwhen different UEs select the same resource as the PSSCH.

If less frequency resources are used for the PSSCH by reducing Z as lessfrequency resources are occupied by the PSSCH, the amount of necessaryPSCCH candidate resources may be guaranteed even when an influence ofIBE is slightly raised. Similarly to the above description, when thePSCCH has a plurality of formats each requiring a different size ofresources, the value of Z may be differently set according to a formatof the PSCCH. For example, for a format of the PSCCH requiring a largersize of resources, an operation of determining the location of acandidate resource to have a relatively large value of Z may beperformed.

In the above description, when the PSCCH candidate resources areassociated with the PSSCH candidate resources, the PSCCH transmitted onat least a part of the PSCCH candidate resources may include controlinformation for the PSSCH transmitted on the PSSCH candidate resourcesor feedback information of the PSSCH. More specifically, when the PSSCHcandidate resources are associated with the PSCCH candidate resources,this means that, when a specific UE transmits the PSSCH using a specificPSSCH candidate resource, the PSCCH associated with this PSSCH istransmitted using a part or all of the associated PSCCH candidateresources. Alternatively, this means that the associated PSCCH is notpermitted to use non-associated PSCCH candidate resources. Theassociated PSCCH may include SA information carrying information neededto receive a corresponding PSSCH or include feedback informationregarding the PSSCH. While embodiments have been described forconvenience on the assumption that the PSCCH is transmitted earlier thanthe PSSCH, the embodiments are applicable to the case in which the PSCCHis transmitted later than the PSSCH (especially, when the PSCCH carriesfeedback information for the PSSCH) and to the case in which the PSCCHand the PSSCH are transmitted on partial time resources at the same timeusing different frequencies. If specific frequency resources become thePSSCH candidate resources, the PSCCH candidate resources associated withthe PSSCH candidate resources may be the same frequency resources as thePSSCH candidate resources located on preceding or following symbols inthe same slot. FIG. 36 illustrates an example (a) in which a PSCCHcandidate resource precedes a PSSCH candidate resource and an example(b) in which the PSCCH candidate resource follows the PSSCH candidateresource. As an alternative to this embodiment, the associated PSCCH andPSSCH candidate resources may be placed at the same frequency locationseparated by a predetermined number of slots.

The value of Z may correspond to X % of the number of RBs correspondingto the PSCCH candidate resources. That is, as illustrated in FIG. 37(a),a region corresponding to X % of all PSCCH candidate regions (3sub-channels) may be selected as actually available PSCCH candidateresources.

The value of X may be determined by at least one of a channel busy ratio(CBR), priority, latency, or reliability. X may have a small value as aUE or a packet has a high priority. Alternatively, a UE having a highpriority may be set to have a higher value of X than adjacent UEs. Insome case, the value of X may be set to select a PSCCH region in one ormore sub-channels or within one sub-channel.

A ratio of the actually available PSCCH candidate resources may beadjusted according to a different situation. For example, when the sizeof actually used PSSCH frequency resources is relatively large,sufficient frequency resources are allocated to the actual PSCCHcandidate resources even when the value of X becomes small. However,when the size of the actually used PSSCH frequency resources isrelatively small, resources necessary for the PSCCH may not be securedwhen the value of X is small. To overcome this problem, if the size ofthe actually used PSSCH frequency resources becomes small, an operationof relatively increasing the value of X may be performed to alwaysguarantee a predetermined level of PSCCH candidate resources. As asimple example, the size of the actually used PSSCH frequency resourcesmay be divided into predetermined sections and the value of X used ineach section may be differently set. For example, when the PSSCHoccupies 10 RBs or more, X may be set to 50% and, when the PSSCHoccupies less than 10 RBs, X may be set to 100%. As another example,when the PSCCH has a plurality of formats each requiring a differentsize of resources, X may be differently set according to a format of thePSCCH. For example, for a format of the PSCCH requiring a larger size ofresources, an operation of determining the location of a candidateresource to have a relatively large value of X may be performed.

While some of resources occupied by the PSSCH may be determined ascandidate locations and then the PSCCH region may be selected within thecandidate locations as illustrated in FIG. 37(a), some resources may beexcluded from the candidate locations and then the PSCCH region may beselected within the candidate locations as illustrated in FIG. 37(b).FIG. 37(b) illustrates the case in which the PSCCH region is selectedfrom locations except for sub-channels of Y % of both ends. The value ofY may be determined by CBR/priority/latency/reliability. As an example,a UE having a high priority may be set to have a smaller or larger valueof Y than adjacent UEs. In some cases, the value of Y may be set toselect the PSCCH region except for a region corresponding to one or moresub-channels or a region smaller than one sub-channel.

Meanwhile, the PSCCH candidate resources may not include a sub-channellocated at an edge of a total frequency bandwidth. That is, the abovedescription may not be applied to a frequency edge. That is, when thePSCCH candidate resources include a sub-channel located at the edge ofthe total frequency bandwidth, the PSCCH candidate resources may beincluded in the sub-channel located at the edge as illustrated in FIG.38 . This is because IBE may be effectively reduced when actual PSCCHcandidate resources are located at the edge of a system frequency regionrather than at a center of a PSSCH frequency region.

In the above-described proposed method, the PSCCH may be transmittedwithin a UE on a specific frequency resource. A region in which thePSCCH is transmitted may be predetermined or a rule may be defined suchthat an eNB informs a UE or a transmission UE informs a reception UE,through a predefined signal (e.g., a physical layer signal or a higherlayer signal). Here, the values of X, Y, and Z may be predefined or maybe configured by a network.

The above description is not limited only to device-to-devicecommunication and may be used on UL or DL. In this case, an eNB or arelay node may use the above proposed method.

Since examples of the above-described proposed methods may be includedin one of implementation methods, it is obvious that the examples may beregarded as proposed methods. Although the above-described proposedmethods may be independently implemented, the proposed methods may beimplemented in a combined (added) form of parts of the proposed methods.A rule may be defined such that information as to whether the proposedmethods are applied (or information about rules of the proposed methods)is indicated by the eNB to the UE or by the transmission UE to thereception UE through a predefined signal (e.g., a physical layer signalor a higher-layer signal).

Overview of Device according to the Embodiment of the Present Disclosure

Hereinafter, a device to which the present disclosure is applicable willbe described.

FIG. 39 illustrates a wireless communication device according to oneembodiment of the present disclosure.

Referring to FIG. 39 , a wireless communication system may include afirst device 9010 and a second device 9020.

The first device 9010 may be a device related to a base station, anetwork node, a transmitting user equipment (UE), a receiving UE, aradio device, a wireless communication device, a vehicle, a vehicle onwhich a self-driving function is mounted, a connected car, a drone(unmanned aerial vehicle (UAV)), an artificial intelligence (AI) module,a robot, an augmented reality (AR) device, a virtual reality (VR)device, a mixed reality (MR) device, a hologram device, a public safetydevice, an MTC device, an IoT device, a medical device, a FinTech device(or financial device), a security device, a climate/environment device,a device related to 5G service or a device related to the fourthindustrial revolution field in addition to the devices.

The second device 9020 may be a device related to a base station, anetwork node, a transmitting UE, a receiving UE, a radio device, awireless communication device, a vehicle, a vehicle on which aself-driving function is mounted, a connected car, a drone (unmannedaerial vehicle (UAV)), an artificial intelligence (AI) module, a robot,an augmented reality (AR) device, a virtual reality (VR) device, a mixedreality (MR) device, a hologram device, a public safety device, an MTCdevice, an IoT device, a medical device, a FinTech device (or financialdevice), a security device, a climate/environment device, a devicerelated to 5G service or a device related to the fourth industrialrevolution field in addition to the devices.

For example, the UE may include a portable phone, a smart phone, alaptop computer, a terminal for digital broadcasting, a personal digitalassistants (PDA), a portable multimedia player (PMP), a navigator, aslate PC, a tablet PC, an ultrabook, a wearable device (e.g., a watchtype terminal (smartwatch), a glasses type terminal (smart glasses), ahead mounted display (HMD)), and so on. For example, the HMD may be adisplay device of a form, which is worn on the head. For example, theHMD may be used to implement VR, AR or MR.

For example, the drone may be a flight vehicle that flies by a wirelesscontrol signal without a person being on the flight vehicle. Forexample, the VR device may include a device implementing an object orbackground of a virtual world. For example, the AR device may include adevice implementing an object or background of a virtual world byconnecting it to an object or background of a real world. For example,the MR device may include a device implementing the object or backgroundof the virtual world by merging it with the object or background of thereal world. For example, the hologram device may include a deviceimplementing a 360-degree stereographic image by recording and playingback stereographic information using the interference phenomenon oflight generated when two lasers called holography meet each other. Forexample, the public safety device may include a video relay device or avideo device capable of being worn on a user's body. For example, theMTC device and the IoT device may be devices that do not require aperson's direct intervention or manipulation. For example, the MTCdevice and the IoT device may include a smart meter, a vending machine,a thermometer, a smart bulb, a door lock or a variety of sensors. Forexample, the medical device may be a device used for the purpose ofdiagnosing, treating, reducing, handling or preventing a disease. Forexample, the medical device may be a device used for the purpose ofdiagnosing, treating, reducing or correcting an injury or obstacle. Forexample, the medical device may be a device used for the purpose oftesting, substituting or modifying a structure or function. For example,the medical device may be a device used for the purpose of controllingpregnancy. For example, the medical device may include a device formedical treatment, a device for operation, a device for (external)diagnosis, a hearing aid or a device for a surgical procedure. Forexample, the security device may be a device installed to prevent apossible danger and to maintain safety. For example, the security devicemay be a camera, CCTV, a recorder or a blackbox. For example, theFinTech device may be a device capable of providing financial services,such as mobile payment. For example, the FinTech device may include apayment device or point of sales (POS). For example, theclimate/environment device may include a device for monitoring orpredicting the climate/environment.

The first device 9010 may include at least one processor such as aprocessor 9011, at least one memory device such as memory 9012, and atleast one transceiver such as a transceiver 9013. The processor 9011 mayperform the above-described functions, procedures, and/or methods. Theprocessor 9011 may implement one or more protocols. For example, theprocessor 9011 may implement one or more layers of a radio interfaceprotocol. The memory 9012 is connected to the processor 9011, and maystore various types of information and/or instructions. The transceiver9013 is connected to the processor 9011, and may be controlled totransmit and receive radio signals. The transceiver 9013 may beconnected with one or more antennas 9014-1 to 9014-n, and thetransceiver 9013 may be configured to transmit and receive user data,control information, a radio signal/channel, which are mentioned in themethods and/or operation flow chart in this specification, through oneor more antennas 9014-1 to 9014-n. In this specification, the n antennasmay be the number of physical antennas or the number of logical antennaports.

The second device 9020 may include at least one processor such as aprocessor 9021, at least one memory device such as memory 9022, and atleast one transceiver such as a transceiver 9023. The processor 9021 mayperform the above-described functions, procedures and/or methods. Theprocessor 9021 may implement one or more protocols. For example, theprocessor 9021 may implement one or more layers of a radio interfaceprotocol. The memory 9022 is connected to the processor 9021, and maystore various types of information and/or instructions. The transceiver9023 is connected to the processor 9021 and may be controlled totransmit and receive radio signals. The transceiver 9023 may beconnected with one or more antennas 9024-1 to 9024-n, and thetransceiver 9023 may be configured to transmit and receive user data,control information, a radio signal/channel, which are mentioned in themethods and/or operation flow chart in this specification, through oneor more antennas 9024-1 to 9024-n.

The memory 9012 and/or the memory 9022 may be connected inside oroutside the processor 9011 and/or the processor 9021, respectively, andmay be connected to another processor through various technologies, suchas a wired or wireless connection. FIG. 40 illustrates a wirelesscommunication device according to an implementation of the presentdisclosure.

FIG. 40 shows a more detailed view of the first or second device 9010 or9020 of FIG. 39 . However, the wireless communication device of FIG. 40is not limited to the first or second device 9010 or 9020. The wirelesscommunication device may be any suitable mobile computing device forimplementing at least one configuration of the present disclosure suchas a vehicle communication system or device, a wearable device, aportable computer, a smart phone, etc.

Referring to FIG. 40 , the wireless communication device (UE) mayinclude at least one processor (e.g., DSP, microprocessor, etc.) such asa processor 9110, a transceiver 9135, a power management module 9105, anantenna 9140, a battery 9155, a display 9115, a keypad 9120, a GPS chip9160, a sensor 9165, a memory 9130, a subscriber identification module(SIM) card 9125 (which is optional), a speaker 9145, and a microphone9150. The UE may include at least one antennas.

The processor 9110 may be configured to implement the above-describedfunctions, procedures, and/or methods. In some implementations, theprocessor 9110 may implement one or more protocols such as radiointerface protocol layers.

The memory 9130 is connected to the processor 9110 and may storeinformation related to the operations of the processor 9110. The memory9130 may be located inside or outside the processor 9110 and connectedto other processors through various techniques such as wired or wirelessconnections.

A user may enter various types of information (e.g., instructionalinformation such as a telephone number) by various techniques such aspushing buttons of the keypad 9120 or voice activation using themicrophone 9150. The processor 9110 may receive and process theinformation from the user and perform appropriate functions such asdialing the telephone number. For example, the processor 9110 data mayretrieve data (e.g., operational data) from the SIM card 9125 or thememory 9130 to perform the functions. As another example, the processor9110 may receive and process GPS information from the GPS chip 9160 toperform functions related to the location of the UE, such as vehiclenavigation, map services, etc. As a further example, the processor 9110may display various types of information and data on the display 9115for user reference and convenience.

The transceiver 9135 is connected to the processor 9110 and may transmitand receives a radio signal such as an RF signal. The processor 9110 maycontrol the transceiver 9135 to initiate communication and transmitradio signals including various types of information or data such asvoice communication data. The transceiver 9135 includes a receiver and atransmitter to receive and transmit radio signals. The antenna 9140facilitates the radio signal transmission and reception. In someimplementations, upon receiving radio signals, the transceiver 9135 mayforward and convert the signals to baseband frequency for processing bythe processor 9110. Various techniques may be applied to the processedsignals. For example, the processed signals may be transformed intoaudible or readable information to be output via the speaker 9145.

In some implementations, the sensor 9165 may be coupled to the processor9110. The sensor 9165 may include one or more sensing devices configuredto detect various types of information including, but not limited to,speed, acceleration, light, vibration, proximity, location, image, andso on. The processor 9110 may receive and process sensor informationobtained from the sensor 9165 and perform various types of functionssuch as collision avoidance, autonomous driving, etc.

In the example of FIG. 40 , various components (e.g., camera, universalserial bus (USB) port, etc.) may be further included in the UE. Forexample, a camera may be coupled to the processor 9110 and used forvarious services such as autonomous driving, vehicle safety services,etc.

The UE of FIG. 40 is merely exemplary, and implementations are notlimited thereto. That is, in some scenarios, some components (e.g.,keypad 9120, GPS chip 9160, sensor 9165, speaker 9145, and/or microphone9150) may not be implemented in the UE.

FIG. 41 illustrates a transceiver of a wireless communication deviceaccording to an implementation of the present disclosure. Specifically,FIG. 41 shows a transceiver that may be implemented in a frequencydivision duplex (FDD) system.

In the transmission path, at least one processor such as the processordescribed in FIGS. 23 and 24 may process data to be transmitted and thentransmit a signal such as an analog output signal to a transmitter 9210.

In the transmitter 9210, the analog output signal may be filtered by alow-pass filter (LPF) 9211, for example, to remove noises caused byprior digital-to-analog conversion (ADC), upconverted from baseband toRF by an upconverter (e.g., mixer) 9212, and amplified by an amplifier9213 such as a variable gain amplifier (VGA). The amplified signal maybe filtered again by a filter 9214, further amplified by a poweramplifier (PA) 9215, routed through duplexer 9250 and antenna switch9260, and transmitted via an antenna 9270.

In the reception path, the antenna 9270 may receive a signal in awireless environment. The received signal may be routed through theantenna switch 9260 and duplexer 9250 and sent to a receiver 9220.

In the receiver 9220, the received signal may be amplified by anamplifier such as a low noise amplifier (LNA) 9223, filtered by aband-pass filter 9224, and downconverted from RF to baseband by adownconverter (e.g., mixer) 9225.

The downconverted signal may be filtered by an LPF 9226 and amplified byan amplifier such as a VGA 9227 to obtain an analog input signal, whichis provided to the at least one processor such as the processor.

Further, a local oscillator (LO) 9240 may generate and providetransmission and reception LO signals to the upconverter 9212 anddownconverter 9225, respectively.

In some implementations, a phase locked loop (PLL) 9230 may receivecontrol information from the processor and provide control signals tothe LO 9240 to generate the transmission and reception LO signals atappropriate frequencies.

Implementations are not limited to the particular arrangement shown inFIG. 41 , and various components and circuits may be arrangeddifferently from the example shown in FIG. 41 .

FIG. 42 illustrates a transceiver of a wireless communication deviceaccording to an implementation of the present disclosure. Specifically,FIG. 42 shows a transceiver that may be implemented in a time divisionduplex (TDD) system.

In some implementations, a transmitter 9310 and a receiver 9320 of thetransceiver in the TDD system may have one or more similar features tothose of the transmitter and the receiver of the transceiver in the FDDsystem. Hereinafter, the structure of the transceiver in the TDD systemwill be described.

In the transmission path, a signal amplified by a PA 9315 of thetransmitter may be routed through a band selection switch 9350, a BPF9360, and an antenna switch(s) 9370 and then transmitted via an antenna9380.

In the reception path, the antenna 9380 may receive a signal in awireless environment. The received signals may be routed through theantenna switch(s) 9370, the BPF 9360, and the band selection switch 9350and then provided to the receiver 9320.

FIG. 43 illustrates sidelink operations of a wireless device accordingto an implementation of the present disclosure. The sidelink operationsof the wireless device shown in FIG. 43 are merely exemplary, and thewireless device may perform sidelink operations based on varioustechniques. The sidelink may correspond to a UE-to-UE interface forsidelink communication and/or sidelink discovery. The sidelink maycorrespond to a PC5 interface as well. In a broad sense, the sidelinkoperation may mean information transmission and reception between UEs.Various types of information may be transferred through the sidelink.

Referring to FIG. 43 , the wireless device may obtain sidelink-relatedinformation in step S9410. The sidelink-related information may includeat least one resource configuration. The wireless device may obtain thesidelink-related information from another wireless device or a networknode.

After obtaining the sidelink-related information, the wireless devicemay decode the sidelink-related information in step S9420.

After decoding the sidelink-related information, the wireless device mayperform one or more sidelink operations based on the sidelink-relatedinformation in step S9430. The sidelink operation(s) performed by thewireless device may include at least one of the operations describedherein.

FIG. 44 illustrates sidelink operations of a network node according toan implementation of the present disclosure. The sidelink operations ofthe network node shown in FIG. 44 are merely exemplary, and the networknode may perform sidelink operations based on various techniques.

Referring to FIG. 44 , the network node may receive sidelink-relatedinformation from a wireless device in step S9510. For example, thesidelink-related information may correspond to Sidelink UE Information,which is used to provide sidelink information to a network node.

After receiving the sidelink-related information, the network node maydetermine whether to transmit one or more sidelink-related instructionsbased on the received information in step S9520.

When determining to transmit the sidelink-related instruction(s), thenetwork node may transmit the sidelink-related instruction(s) to thewireless device in S9530. In some implementations, upon receiving theinstruction(s) transmitted from the network node, the wireless devicemay perform one or more sidelink operations based on the receivedinstruction(s).

FIG. 45 illustrates the implementation of a wireless device and anetwork node according to an implementation of the present disclosure.The network node may be replaced with a wireless device or a UE.

Referring to FIG. 45 , a wireless device 9610 may include acommunication interface 9611 to communicate with one or more otherwireless devices, network nodes, and/or other entities in the network.The communication interface 9611 may include one or more transmitters,one or more receivers, and/or one or more communications interfaces. Thewireless device 9610 may include a processing circuitry 9612. Theprocessing circuitry 9612 may include at least one processor such as aprocessor 9613 and at least one memory such as a memory 9614.

The processing circuitry 9612 may be configured to control at least oneof the methods and/or processes described herein and/or enable thewireless device 9610 to perform the methods and/or processes. Theprocessor 9613 may correspond to one or more processors for performingthe wireless device functions described herein. The wireless device 9610may include the memory 9614 configured to store the data, programmablesoftware code, and/or information described herein.

In some implementations, the memory 9614 may store software code 9615including instructions that allow the processor 9613 to perform some orall of the above-described processes when driven by the at least oneprocessor such as the processor 9613.

For example, the at least one processor such as the processor 9613configured to control at least one transceiver such as a transceiver2223 may process at least one processor for information transmission andreception.

A network node 9620 may include a communication interface 9621 tocommunicate with one or more other network nodes, wireless devices,and/or other entities in the network. The communication interface 9621may include one or more transmitters, one or more receivers, and/or oneor more communications interfaces. The network node 9620 may include aprocessing circuitry 9622. The processing circuitry 9622 may include aprocessor 9623 and a memory 9624.

In some implementations, the memory 9624 may store software code 9625including instructions that allow the processor 9623 to perform some orall of the above-described processes when driven by at least oneprocessor such as the processor 9623.

For example, the at least one processor such as the processor 9623configured to control at least one transceiver such as a transceiver2213 may process at least one processor for information transmission andreception.

The above-described implementations may be embodied by combining thestructural elements and features of the present disclosure in variousways. Each structural element and feature may be selectively consideredunless specified otherwise. Some structural elements and features may beimplemented without any combination with other structural elements andfeatures. However, some structural elements and features may be combinedto implement the present disclosure. The operation order describedherein may be changed. Some structural elements or feature in animplementation may be included in another implementation or replacedwith structural elements or features suitable for the otherimplementation.

The above-described implementations of the present disclosure may beembodied through various means, for example, hardware, firmware,software, or any combination thereof. In a hardware configuration, themethods according the present disclosure may be achieved by at least oneof one or more ASICs, one or more DSPs, one or more DSPDs, one or morePLDs, one or more FPGAs, one or more processors, one or morecontrollers, one or more microcontrollers, one or more microprocessors,etc.

In a firmware or software configuration, the methods according to thepresent disclosure may be implemented in the form of a module, aprocedure, a function, etc. Software code may be stored in a memory andexecuted by a processor. The memory may be located inside or outside theprocessor and exchange data with the processor via various known means.

Those skilled in the art will appreciate that the present disclosure maybe carried out in other specific ways than those set forth hereinwithout departing from the spirit and essential characteristics of thepresent disclosure. Although the present disclosure has been describedbased on the 3GPP LTE/LTE-A system or 5G system (NR system), the presentdisclosure is also applicable to various wireless communication systems.

The above-described implementations are applicable to various mobilecommunication systems.

What is claimed is:
 1. A method of transmitting a physical sidelinkcontrol channel (PSCCH) by a sidelink user equipment (UE) in a wirelesscommunication system, the method comprising: determining PSCCH candidateresources associated with physical sidelink shared channel (PSSCH)candidate resources; and transmitting a PSCCH using at least someresources among the PSCCH candidate resources, wherein the at least someresources include Z successive resource blocks (RBs) and include acenter frequency of the PSCCH candidate resources on a frequency axis.2. The method of claim 1, wherein Z is uniform regardless of change in asize of the associated PSSCH candidate resources.
 3. The method of claim1, wherein a resource region irrelevant to the resources used totransmit the PSCCH is related to a guard band of the PSCCH.
 4. Themethod of claim 1, wherein the PSCCH candidate resources associated withthe PSSCH candidate resources have a size of a frequency resource regionequal to a size of a frequency resource region of the PSSCH candidateresources.
 5. The method of claim 1, wherein, based on the PSCCHcandidate resources associated with the PSSCH candidate resources, thePSCCH transmitted on some of the PSCCH candidate resources includescontrol information for a PSSCH transmitted on the PSSCH candidateresources or feedback information of the PSSCH.
 6. The method of claim1, wherein Z is related to X % of the number of RBs related to the PSCCHcandidate resources.
 7. The method of claim 6, wherein X is determinedby at least one of a channel busy ratio (CBR), priority, latency, orreliability.
 8. The method of claim 7, wherein X has a small value asthe UE or a packet has a high priority.
 9. The method of claim 6,wherein X is set with respect to each format of the PSCCH.
 10. Themethod of claim 1, wherein the PSCCH candidate resources do not includea sub-channel located at an edge of a total frequency bandwidth.
 11. Themethod of claim 1, wherein, based on the PSCCH candidate resourcesincluding a sub-channel located at an edge of a total frequencybandwidth, the PSCCH transmission resources are included in asub-channel located at the edge.
 12. The method of claim 1, wherein theat least some resources are selected from a resource region excluding asub-channel of Y % of the PSCCH candidate resources.
 13. The method ofclaim 12, wherein Y is determined by at least one of a channel busyratio (CBR), priority, latency, or reliability.
 14. A sidelink userequipment (UE) for transmitting a physical sidelink control channel(PSCCH) in a wireless communication system, the sidelink UE comprising:a memory; and a processor coupled to the memory, wherein the processoris configured to transmit a PSCCH using at least some resources amongPSCCH candidate resources associated with physical sidelink sharedchannel (PSSCH) candidate resources, and wherein the resources used totransmit the PSCCH include Z successive resource blocks (RBs) andinclude a center frequency of the PSCCH candidate resources on afrequency axis.
 15. The sidelink UE of claim 1, wherein the UE is anautonomous driving vehicle or is included in the autonomous drivingvehicle.